avian medicine: princilpes and application · 2011-11-26 · principles and application linda r....

BRANSON W. RITCHIE, DVM, PhD Assistant Professor, Avian and Zoologic Medicine Department of Small Animal Medicine College of Veterinary Medicine University of Georgia Athens, Georgia

GREG J. HARRISON, DVM Director, The Bird Hospital Lake Worth, Florida President, Harrison’s Bird Diets Omaha, Nebraska

LINDA R. HARRISON, BS President, Wingers Publishing, Inc. Former Editor, Journal of the Association of Avian Veterinarians Lake Worth, Florida

AVIAN MEDICINE: PRINCIPLES AND APPLICATION

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nowledge of the principles and techniquesof supportive care and emergency medicineis necessary for the successful medicalmanagement of avian patients. The basic

concepts of emergency and supportive care of smallanimal medicine apply to birds, but modificationsmust be made to compensate for their unique anat-omy and physiology. Supportive care including fluidtherapy, nutritional support, and heat and oxygensupplementation is critical to both emergency andmaintenance therapy.

Emergencies of many different types are seen inavian medicine. A common emergency is the ex-tremely debilitated, cachectic, chronically ill birdthat is too weak to perch or eat. Because certainsyndromes are more common in certain species andat certain ages, the signalment of the bird is helpfulin establishing a rule-out list. Recently obtainedbirds frequently present with acute infectious prob-lems, including chlamydiosis and viral diseases.

Neonates that are being hand-fed commonly sufferfrom management-related problems (eg, crop burns,nutritional deficiencies) and certain fungal, bacterialand viral diseases such as candidiasis, gram-nega-tive ingluvitis and avian polyomavirus. Birds thatare long-term companion animals are more likely tohave chronic infectious diseases such as aspergil-losis, chronic nutritional diseases or toxicities. Eggbinding and egg-related peritonitis frequently occurin companion budgerigars and cockatiels. Aviarybirds can have a variety of infectious, metabolic, toxicand nutritional problems. Traumatic emergenciesare common in all types of birds.

Critically sick or injured birds are often too weak foran extensive examination when first presented.Birds that are on the bottom of the cage and dyspneicneed immediate medical attention with an organ-ized, efficient approach to stabilization therapy.Physical examination, diagnostic tests and treat-ments should be performed in intermittent steps todecrease restraint periods and reduce stress.

KC H A P T E R

15SUPPORTIVE CARE

AND EMERGENCY

THERAPY

Katherine E. QuesenberryElizabeth V. Hillyer

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Avian Medecine : Principles and Application, B.W. Ritchie, G.J Harrison and L.R. Harrison (Eds.)

Emergency Stabilization

Although each bird should be evaluated individually,some basic guidelines for emergency diagnostic test-ing and treatment can be followed. The bird shouldbe observed carefully in its enclosure before han-dling, to assess the depth and rate of breathing. Birdswith airway obstruction or severe respiratory diseaseare usually extremely dyspneic. Birds that are sep-ticemic, in shock or weak from chronic disease mayalso have labored breathing. If respiration is rapid ordifficult, the bird should be placed immediately in anoxygen cage. This is usually less stressful than usinga face mask, especially if the bird is refractory torestraint. While the bird is allowed to stabilize, acomplete history can be obtained from the owner, anda diagnostic and therapeutic plan based on the his-tory, clinical signs and the initial physical findingscan be formulated.

If the bird can be weighed without undue stress, anaccurate pretreatment weight should be obtained.Otherwise, drug dosages are calculated based on anestimate of the body weight for the species (see Chap-ter 30). The most important treatments must begiven first. If the bird shows any signs of stressduring restraint, it may be placed back in oxygen orin a quiet enclosure until it is stable. Alternatively,the bird can be given oxygen by face mask whiletreatments are administered.

Some veterinarians prefer to use isoflurane anesthe-sia when treating very weak, dyspneic or fractiousbirds. For gradual induction in critically ill patients,low isoflurane concentrations (0.25%) are slowly in-creased to 1.5% or 2.5% over two to five minutes.Once the bird is anesthetized, lower maintenanceconcentrations (0.75% to 2%) can be used. Birds canbe maintained with a face mask or intubated.

The use of anesthesia allows several procedures to beperformed within a few minutes, including collectionof a blood sample, placement of a catheter or air sactube and radiographs. For each bird, the risk ofanesthesia must be considered and weighed againstthe risks of stress associated with manual restraint.If anesthesia is chosen for restraint, the episodeshould be of short duration and the bird must becarefully monitored.

Pretreatment blood samples are valuable if appropri-ate to obtain. If intravenous fluids are given, a sam-ple can be obtained through a butterfly catheter inthe jugular vein immediately before fluid admini-stration. The bird should be evaluated for anemiabefore blood is withdrawn. If the conjunctiva andmucous membranes appear pale, the packed cell vol-ume (PCV) should be determined by taking a smallblood sample from a toenail clip. If the PCV is 15% orless, collecting blood for a full biochemistry analysisor complete blood count can be life-threatening. Col-lecting a pretreatment blood sample is usually toostressful in extremely dyspneic birds unless anesthe-sia is used for restraint.

While the bird is resting after the initial treatments,necessary diagnostic samples collected during therestraint period (eg, fecal or crop cultures, chlamydiatest, blood work) can be evaluated. Radiographs areusually postponed until the bird is stable. If radio-graphs are essential for establishing a correct diag-nosis and initiating treatment, isoflurane anesthesiacan be used to ensure that diagnostic radiographs aresafely obtained.

Fluid Replacement Therapy

Fluid RequirementsThe daily maintenance fluid requirement for raptorsand psittacine birds has been estimated at 50ml/kg/day (5% of the body weight).42 This estimate isappropriate clinically for most companion and aviarybird species. However, water consumption may varyfrom 5 to 30% of body weight per day in many free-ranging species. The amount of water needed is gen-erally inversely related to body size3 and can alsovary according to age, reproductive status, dietaryintake and the type of foods consumed (Table 15.1).

TABLE 15.1 Variance in Water Intake

Adult chickens 5.5% bw/day15

Cockatiels 5-8% bw/dayGrowing chickens 18-20% bw/dayLaying hens 13.6% bw/day63

An estimate of hydration status is based on theclinical signs and history. The turgescence, fillingtime and luminal volume of the ulnar vein and arteryare good indicators of hydration status.1 A filling timeof greater than one to two seconds in the ulnar veinindicates dehydration greater than seven percent.Severely dehydrated birds (ten percent) may have

CHAPTER 15 SUPPORTIVE CARE AND EMERGENCY THERAPY

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sunken eyes and tacky mucous membranes. The skinof the eyelids may tent when pinched.

As for mammals, anemia or hypoproteinemia canaffect the accuracy of a PCV or total solids in detect-ing dehydration (Table 15.2).

TABLE 15.2 Findings with Dehydration31,33

Increased PCV 15 to 30%Increased total solids 20 to 40%Increased plasma urea 6.5 to 15.3 x normal

Changes will vary with the degree of dehydration.

Most birds presented as emergencies have a historyof inadequate water intake and can be assumed to beat least five percent dehydrated. An estimation of thefluid deficit can be calculated based on body weight:

Estimated dehydration (%) x body weight (grams) = fluid deficit (ml)18

Half of the total fluid deficit is given over the first 12to 24 hours along with the daily maintenance fluidrequirement. The remaining 50% is divided over thefollowing 48 hours with the daily maintenance fluids.

Lactated Ringer’s solution (LRS) or a similar bal-anced isotonic solution warmed to 100.4° to 102.2°F(38° to 39°C) is recommended for fluid replacementand shock therapy. Using warm fluids is particularlyimportant with neonates and with intravenous orintraosseous administration of fluids for hypother-mia or shock.1

The exact fluid requirements of birds in shock aredifficult to determine. In mammals in septic shock, afluid volume of 0.5 to 1.5 times the estimated bloodvolume may be needed to correct peripheral vasocon-striction. Thirty minutes after treatment, only 25%of administered isotonic crystalloid fluids remains inthe vascular compartment.21 The remaining 75% re-distributes to the interstitial fluid compartment.Consequently, circulatory improvement may be tran-sient, requiring additional fluid therapy to preventrecurrence of hypotension and vasoconstriction.

As illustrated by this example, hemodilution is theprimary limitation to crystalloid fluid therapy, mak-ing administration of colloids or blood necessary foreffective shock therapy. Synthetic colloid solutions(dextran, hetastarch) have not been used to any ex-tent in birds. These solutions contain large moleculesthat do not cross the endothelium and remain in theintravascular fluid compartment. Colloid solutionsdraw fluid from the interstitial fluid compartment

into the intravascular space and are more effectiveblood volume expanders than crystalloids.1,21 Theyare particularly useful in restoring circulating bloodvolume without aggravating hypoproteinemia orcausing pulmonary edema in animals with low onco-tic pressure and hypoproteinemia.

There is evidence that hemorrhagic shock does notoccur in birds.64 Severe blood loss is tolerated muchbetter in birds than in mammals, especially inflighted birds. This tolerance is the result of an in-creased rate of absorption of tissue fluids to replacelost blood volume and baroreceptor reflexes, whichmaintain normal blood pressure. Prostaglandins,which potentiate shock in mammals, have beenshown to have no effect in chickens.

Route of Fluid TherapySupplemental fluids can be given orally, subcutane-ously, intravenously or by intraosseous cannula (Fig-ure 15.1). Fluids can be given orally for rehydrationand maintenance in birds that are mildly dehy-drated. Oral rehydration is often used for waterfowland other large species in which administration ofintravenous or subcutaneous fluids is difficult. Inpigeons, administration of an oral five percent dex-trose solution has been shown to be more effective forrehydration than oral administration of lactatedRinger’s solution.33 This effect may be the result ofglucose causing a more rapid uptake of water fromthe intestinal tract. Gatoradew is used by some vet-erinarians for oral rehydration and fluid mainte-nance. For effective rehydration, oral fluids need tobe readministered within 60 to 90 minutes of the firsttreatment. Mixing oral fluids with pysilliuma mayincrease fluid and calcium absorption from the intes-tinal villi. Oral fluids should not be given to birdsthat are seizuring, laterally recumbent, regurgitat-ing, in shock or have gastrointestinal stasis.

Subcutaneous administration is used primarily formaintenance fluid therapy. The axilla and lateralflank areas are commonly used for injection. Theintrascapular area is preferred by some clinicians inyoung birds that may be difficult to restrain for flankinjection. The area around the neck base should beavoided because of the extensive communications ofthe cervicocephalic air sac system. A small (25 to 27ga) needle is used to prevent fluids from leaking fromthe injection site. The total volume of fluids shouldbe given in several sites (5 to 10 ml/kg/site) to preventdisruption of blood flow and subsequent poor absorp-tion.1 Subcutaneous fluids are less effective than in-travenous or intraosseous fluids for shock therapy

SECTION THREE TREATMENT REGIMENS

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because of peripheral vasoconstriction. Subcutane-ous fluids may pool in the ventral abdominal areacausing hypoproteinemia, overhydration or poor ab-sorption. If ventral abdominal edema is noted, subcu-taneous fluid administration should be decreased ordiscontinued.

Intravenous fluids are necessary in cases of shock tofacilitate rapid rehydration. Intraosseous cannulasor use of the right jugular vein are the best accesspoints to the peripheral circulation. Dyspneic birdsand those with distended, fluid-filled crops should becarefully handled to prevent regurgitation and aspir-ation. Injection of a large fluid volume into the ulnaror metatarsal veins is difficult and frequently resultsin hematoma formation.

A butterfly catheter (25 ga) with 3.5-inch tubing isideal for fluid administration in medium-sized tolarge birds (Figure 15.2). A 27 ga needle can be usedin small birds. The catheter allows pretreatmentblood collection and “slow” administration of fluids,antibiotics or other medications with one venipunc-ture. Drug dosages and fluids should be preparedbefore the bird is restrained.

The amount of fluid that can be administered at onetime depends on the size of the bird. Injections of tenml/kg given slowly over five to seven minutes areusually well tolerated.1 The bolus injections can berepeated every three to four hours for the first twelvehours, every eight hours for the next 48 hours, andthen BID.18

Intravenous catheters (24 ga in medium to largebirds) can be placed in the ulnar or medial metatar-sal veins of some birds for continuous fluid admini-stration. For placement in the ulnar vein, the cathe-ter is inserted using sterile technique, securedloosely with elastic tape24 and fixed in place using atongue depressor that extends 1.5 inches beyond thecatheter end. Both the proximal and distal ends ofthe tongue depressor are then firmly incorporated ina wing wrap to stabilize the catheter.5 The risk ofhematoma formation is probably greater using theulnar vein than with the metatarsal vein.

Maintenance of an IV catheter can be difficult. Manybirds will chew at the catheter, tape or extension settubing.

FIG 15.2 IV fluids and drugs can be slowly administered througha butterfly catheter in the right jugular vein. The biggest disad-vantage to this technique is that fluids should not be given fasterthan 10 ml/kg over a five- to seven-minute period necessitatingprolonged restraint for fluid administration (courtesy of KathyQuesenberry).

FIG 15.1 Subcutaneous fluids can be administered in the lateralflank, axilla or intrascapular region (shown here) in cases of milddehydration (five percent) to provide maintenance fluids. The areaof the base of the neck should be avoided because of the cervico-cephalic air sacs. Subcutaneous fluids are generally ineffective incases of severe dehydration or shock.


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An intraosseous cannula can be used for administra-tion of fluids, blood, antimicrobials, parenteral nutri-tional supplements, colloids, glucose and drugs usedfor cardiovascular resuscitation in birds.36 Admini-stration of hypertonic or alkaline solutions can bepainful and should be avoided. The advantages ofintraosseous cannulas include the ease of placementand maintenance, cannula stability, tolerance bymost birds and reduced patient restraint once thecannula is placed. Continuous fluid administrationby intraosseous cannula is less stressful than re-peated venipunctures.

It has been shown in pigeons that 50% of the fluidsadministered in the ulna enters the systemic circula-tion within 30 seconds.30 Over a two-hour period, theflow into the systemic circulation was almost equiva-lent to the administration rate.

Intraosseous cannulas can be placed in any bonewith a rich marrow cavity.36 A cannula may be placedin the distal ulna in medium-sized to large birds thatwill require several days of therapy (Figure 15.3).The proximal tibia is ideal in birds that will requireshorter terms of therapy. Pneumatic bones such asthe humerus and femur cannot be used. Isofluraneanesthesia is sometimes necessary for cannula place-ment in fractious birds. In medium-sized or largerbirds, an 18 to 22 ga, 1.5 to 2.5 inch spinal needlev canbe used as the cannula. In smaller birds, a 25 to 30ga hypodermic needle is used.

For placement in the ulna, the feathers from thedistal carpus are removed and the area is asepticallyprepared. Using sterile technique, the needle is in-troduced into the center of the distal end of the ulnaparallel to the median plane of the bone (Figure15.4).46 The entry site is ventral to the dorsal condyleof the distal ulna (Figure 15.4). The needle is ad-vanced into the medullary cavity by applying pres-sure with a slight rotating motion. The needle shouldadvance easily with little resistance once the cortexis penetrated. If resistance is encountered, the needlemay have entered the lateral cortex. When seatedcorrectly, a small amount of bone marrow can beaspirated through the cannula. This aspirate can besubmitted for bone marrow analysis if desired. The

CLINICAL APPL ICAT IONSFluid Therapy Considerations

Oral FluidsOnly effective with mild dehydration

5% dextrose may be better than lactated Ringer’s solution

Contraindicated with GI stasis

Contraindicated with lateral recumbency

Contraindicated with seizuring and head trauma

Ineffective for shock

Subcutaneous FluidsPrimarily used for mild dehydration

Effective for providing maintenance fluids

Given in axilla or lateral flank

Divide dose among several sites

Intravenous or Intraosseous FluidsRapidly expands circulatory volume

Rapidly perfuses kidneys

Indicated in shock

Indicated with severe dehydration

Right jugular vein - one time use

Medial metatarsal vein - one time use

Tibial intraosseous cannula - one time use

FIG 15.3 A mature Umbrella Cockatoo was presented with a two-day history of vomiting and profuse diarrhea. The bird was esti-mated to be ten percent dehydrated (reduced ulnar refill time,tacky mucous membranes, dull sunken eyes). PCV=28 and TP=6.8.An intraosseous catheter was placed in the ulna and the bird wasgiven warm LRS using an infusion pump. The clinical response torehydration was dramatic. The bird had destroyed a plastic cupthe day before clinical signs started. Large pieces of plastic wereflushed out of the proventriculus by gastric lavage using warmLRS.


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cannula should be flushed with a small amount ofheparinized saline, which should flow without resis-tance. Initial fluids should be administered slowly tocheck for subcutaneous swelling, which would indi-cate improper placement of the cannula. If the can-nula is properly placed, fluid can be visualized pass-ing through the ulnar vein. The cannula is secured inplace by wrapping a piece of tape around the end andsuturing the tape to the skin or by applying a steriletissue adhesiveb at the point of insertion (Figure15.4). A gauze pad with a small amount of antibact-erial ointment is placed around the cannula at theinsertion site, and a figure-of-eight bandage is usedto secure the wing. One to two loops of the extensiontube should be incorporated into the bandage to de-crease tension on the cannula.

Tibial cannulas are seated in the tibial crest andpassed distally, similar to the technique used forobtaining a bone marrow aspirate. A light paddedbandage or lateral splint is used to secure the can-nula in place (see Figure 39.5).

Fluids are administered through the cannula usingan infusion pump, buretrolc or Control-a-Flow regu-lator.d Unlike a vein, the marrow cavity cannot ex-pand to accommodate rapid infusions of large fluidvolumes. Consequently the rate of infusion into themarrow cavity is limited. The ideal infusion rate toavoid fluid extravasation in birds is unknown. Insmall mammals, fluids can be given at shock doses(90 ml/kg) at a pressurized flow rate of 2 l/hr.36 Clini-cally, infusion rates in birds for shock therapy shouldprobably be much lower. A flow rate of ten ml/kg/hr issuggested for maintenance. Excessively rapid infu-sion of the fluids may cause signs of discomfort oredema of the soft tissue in the area of the cannula.Fluid extravasation may occur if the infused volumeis too large, or if several holes were made in thecortex while attempting to place the cannula.

Intraosseous cannulas are most successful in birds ifused during the first 24 to 48 hours for initial rehy-dration and shock therapy. Cannulas can remain inplace for up to 72 hours without complications ifplaced aseptically and maintained with heparinizedflushings every six hours.36 Clinically, after two tothree days of use, many birds exhibit a painful re-sponse when fluids are given through an in-traosseous cannula. This could result from pain asso-ciated with local edema or the extravasation of fluidsaround the marrow cavity. Some birds will not toler-ate the cannula and will bite at the extension tubingor the wrap as their general condition improves.

FIG 15.4 Technique for placing an intraosseous cannula in thedistal ulna. If fluid or drug administration will be restricted to asingle dose or a short period (eg, surgery), it is easier to place acatheter in the tibia. An intraosseous catheter placed in the ulnais easier to maintain if several days of continuous IV therapy arenecessary. a) The thumb is placed in the center of the 1) ulna as aguide. b) The cannula is inserted slightly ventral to the 2) dorsalcondyle of the distal ulna. The 3) radius and 4) radial carpal bonecan be used for orientation. c) The cannula is sutured in place. d)Radiograph of properly inserted cannula.


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The use of vascular access devices (VAD) in birds hasrecently been described.20 A vascular access deviceconsists of a catheter that is placed within a vessel,and a port that is implanted in the subcutaneoustissue. No portion of the catheter is externally ex-posed, reducing the incidence of bacterial contamina-tion and infection. A specially designed needle(Huber needle) is used for access to the depot port byskin penetration. Use of a VAD allows repeated bloodsampling and drug administration without repeatedvenipuncture, with minimal stress on the patient.Vascular access ports are used in humans primarilyfor long-term intravenous chemotherapy and totalparenteral nutrition. More recently, vascular accessdevices have been used in dogs and laboratory ani-mals.2,37 Potential complications of the vascular ac-cess port include thrombosis, sepsis, local infectionand drug extravasation.2

Vascular access devices have been used experimen-tally in pigeons and geese and clinically in an auk-let.20 The use of the device in small birds may belimited by the size of the animal and absence of anappreciable subcutaneous space. Other disadvan-tages of the device in birds include the necessity ofsurgical placement and removal and the difficulty ofvenotomy in small avian patients.

The system is usually implanted with the animalunder general anesthesia (see Chapter 41). A skinincision is made over the jugular vein. The vein isisolated and occluded cranially for venotomy andinsertion of the catheter. The catheter is secured inplace in the vein with sutures above and below aretention ring on the catheter. A tunnel is madethrough the subcutaneous tissue to a site dorsal tothe catheter where the port is sutured to the under-lying muscle fascia. The extravascular portion of thecatheter is left in a short loop to prevent tensionduring neck movement. The catheter is flushed withheparinized saline at regular intervals to ensurepatency.

AntibioticsSepticemia and bacteremia should be considered inany bird that is severely depressed. Prophylacticantibiotics are frequently used in birds that are im-munocompromised from a noninfectious disease. An-tibiotics are not necessary in all emergencies. Birdswith simple closed fractures, uncomplicated heavymetal toxicity, hypocalcemia and other noninfectiousproblems may not require or benefit from the use ofantibiotics. However, in many emergency patientsthe history and clinical signs are vague and inconclu-

sive, and antibiotics may be indicated on a precau-tionary basis.

Parenteral antibiotics are recommended for the in-itial treatment of birds that are weak, sick, debili-tated or in shock.45 General peak plasma concentra-tions following parenteral drug administration varywith the route: IV = seconds; IM = 30 to 60 minutes;oral = 60 to 120 minutes.

Absorption following oral administration may be er-ratic in birds that are severely dehydrated, havegastrointestinal stasis or are regurgitating. Intrave-nous administration is recommended if septicemia isa primary concern. Intravenous drugs can be givenduring the initial fluid bolus or through an indwell-ing or intraosseous cannula. Intravenous drugsshould be given slowly to avoid circulatory shock.

Intramuscular administration of antibiotics is usedroutinely for maintenance therapy. A small gaugeneedle (26 to 30 ga) is used to minimize muscletrauma. The pectoral muscles should be used formost injections (see Chapter 17).

The major disadvantage to intramuscular injection isthe potential for muscle damage. In a study usinghens, eight of thirteen injectable antibiotic prepara-tions caused muscle necrosis, with the most severedamage being induced by tetracyclines and sul-fonamides. Muscle damage was a common sequela toIM injections of almost 50 different medications inbudgerigars.13

Subcutaneous administration of drugs is less trau-matic to the muscle and is often used for mainte-nance therapy. Subcutaneous injections may be pre-ferred in very small or cachectic birds with limitedmuscle mass and in birds with suspected coagulopa-thies. Disadvantages of subcutaneous injections in-clude the possibility of leakage from the injection siteand poor absorption.

The initial choice of an antibiotic depends on theclinical signs and history of the bird. Birds withsuspected gram-negative septicemia should betreated with a bactericidal antibiotic effectiveagainst the most common avian pathogens, includingEscherichia coli, Enterobacter spp., Klebsiella spp.and Pseudomonas spp.45 Antibiotics commonly usedfor initial treatment of septicemia include piperac-illin, cefotaxime, enrofloxacin, trimethoprim-sulfa,doxycycline and amikacin (see Chapters 17 and 18).


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If chlamydiosis is suspected, the bird should betreated with a parenteral doxycycline to rapidly es-tablish therapeutic blood concentrations and stop theshedding of the organism. After initial parenteraltherapy (IV doxycycline in the United States,e IMdoxycycline in the rest of the worldf), the patient canbe switched to oral medication for continued therapy(see Chapter 34).

Other Drug Therapy

Severe metabolic acidosis is common in mammalsthat are in shock or that are critically ill. In mam-mals in hemorrhagic shock, acidosis occurs secon-dary to inadequate tissue perfusion; however, acido-sis has not been shown to occur in chickens followingprolonged hemorrhage.64 Bicarbonate replacementtherapy has been recommended in birds if severemetabolic acidosis is suspected, but because it is notusually feasible to measure blood gases in birds,bicarbonate deficit must be estimated.18 A dose of 1mEq/kg given IV at 15- to 30-minute intervals to amaximum of 4 mEq has been recommended.42 Insmall animals, bicarbonate must be administeredslowly IV over 20 minutes or longer.21 If administeredtoo rapidly or given in excessive amounts, alkalemia,hypercapnia, hypocalcemia, hypernatremia, hy-perosmolality, hypokalemia and paradoxical CNSacidosis may occur.65 The result may be vomiting,hypotension or death.

Stress causes release of catecholamines, which havehyperglycemic effects. Consequently, birds with trau-matic wounds or chronic, non-septic diseases mayhave normal to increased blood glucose concentra-tions and do not need initial supplemental glucose.Hypoglycemia is most common in sick hand-fed ba-bies, septicemic birds, raptors or extremely cachecticbirds in which body stores of glycogen have beendepleted. In birds that have been determined to behypoglycemic, an IV bolus of 50% dextrose at 2 cc/kgbody weight can be given with fluids to restore bloodglucose concentrations. Glucose can then be added tomaintenance fluids in a 2.5% to 10% solution givenintravenously or intraosseously. Intramuscular in-jections of hyperosmotic (75%) dextrose should not begiven, because severe muscle irritation and necrosiscan result.

Birds that are on poor diets or are chronically illshould receive a parenteral multivitamin on initialhospitalization. Vitamin A and D3u should be admin-istered with care in patients on formulated diets toprevent toxicities from over-supplementation. Vita-

min B complex is suggested both initially and on adaily basis in anorectic or anemic birds. Iron dextrantherapy is also recommended in anemic birds. Vita-min K1 will improve clotting time and is important inbirds with suspected hepatopathies or birds that mayrequire surgery. Vitamin E and selenium should beconsidered in patients that have neuromuscular dis-ease. Supplementation of calcium and iodine may beindicated in some cases.

Recently an injectable amino acid supplementh hasbeen marketed for use in birds. The product has beenrecommended for use as an immune stimulant and anutritional supplement in anorectic and compro-mised birds. Although no scientific studies have beenconducted, some veterinarians report improvementin birds after using this product at recommendeddoses, and no detrimental side effects have beenreported.

CorticosteroidsThe use of corticosteroids in the treatment of shockis controversial. Shock is a very complex disease withmany complicating factors, making it difficult tocompare treatment results in clinical studies. In hu-mans, there are numerous conflicting studies com-paring mortality and reversal of shock in corticos-teroid- versus non-corticosteroid-treated groups.Experimentally, pharmacologic doses of steroidshave anti-shock effects in laboratory animals. Theseinclude improved microcirculation, organelle and cellmembrane stabilization, improved cellular metabo-lism and gluconeogenesis and decreased productionof endogenous toxins.21 Hydrocortisone, pred-nisolone, methylprednisolone and dexamethasoneare recommended in the treatment of hypovolemicand septic shock. There is no definitive evidence ofone drug being superior to another.

Complications of steroid use include immunosup-pression, adrenal suppression, delayed wound heal-ing and gastrointestinal ulceration and bleeding. Ex-cept for immunosuppression, which may occur withone dose of dexamethasone, other negative side ef-fects are primarily associated with chronic therapyusing high dosages.

Prednisolone or dexamethasone are used routinelyfor central nervous system injuries in animals. Meth-ylprednisolone sodium succinate (MPSS) has beenshown to improve recovery in humans and cats withspinal cord injuries.7,8 Dexamethasone was no betterthan a placebo in improving neurologic signs.8 Thebeneficial effects of MPSS are primarily attributed to


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the antioxidant effects in protecting cell membranesfrom lipid peroxidation. It was also found that im-provement was strictly dose-dependent. The optimaldose was 30 mg/kg IV in cats and mice. Lower orhigher dosages were ineffective or even promotedfurther lipid peroxidation. In mice, prednisolone so-dium succinate was found to be equally efficacious,but half as potent, as MPSS when given five minutesafter concussive head injury. Hydrocortisone was in-effective even at high dosages.

There are few studies detailing corticosteroid use inbirds. In Red-tailed Hawks and Barred Owls, bothintravenous and intramuscular injections of dex-amethasone (3 mg/kg) produced peak plasma concen-trations within 15 minutes of injection.9 Intravenousinjections resulted in a higher peak concentration.Serum half-life of dexamethasone varied with thespecies and was found to be 37.5 minutes in Red-tailed Hawks, 53.5 minutes in Barred Owls and 36minutes in male broiler chickens.4 Suppression ofplasma corticosterone concentrations lasted for 24hours in owls and for 18 hours in hawks followingsingle-dose administration. Intramuscular injectionof dexamethasone sodium phosphate (4 mg/kg) inRed-tailed Hawks was associated with elevations inAST and ALT. Elevations were 3.2 times normalvalues within 36 hours of single-dose administra-tion.26 No elevations in AST or ALT were seen follow-ing IV administration.

Corticosteroids are used in birds in the treatment ofshock, acute trauma and toxicities. Clinically, birdsreceiving corticosteroids for head trauma and shocktherapy seem to improve; however, clinical improve-ment may result from supportive care and fluid ther-apy rather than corticosteroid use.

Secondary fungal and bacterial infections are com-mon in birds receiving steroids for longer than oneweek.24 These findings suggest that birds are verysusceptible to the immunosuppressive effects of cor-ticosteroids; therefore, corticorsteroids should beused in birds on an infrequent, short-term basis.

NebulizationNebulization therapy may be beneficial in birds withbacterial or fungal respiratory infections, particu-larly those limited to the upper respiratory system(see Chapter 22). Air sacculitis is frequently associ-ated with the accumulation of inflammatory cells andpathogenic organisms. The caudal thoracic and ab-dominal air sacs are more commonly involved, prob-

ably as a result of the directional air flow within therespiratory system.

The air sac wall consists of a thin layer of simplesquamous epithelial cells supported by a smallamount of connective tissue. Blood supply is ex-tremely limited, and parenteral and oral antimicro-bials that depend on the circulatory system for tissuedistribution are ineffective in treatment of air saccu-litis.27 In effect, nebulization provides topical, local-ized treatment of the internal air sacs and is notdependent on absorption (see Chapter 22). Becauseof the anatomy of the avian respiratory tract and thelack of physical activity in the sick bird, nebulizeddrugs probably reach only 20% of the lung tissue andthe caudal thoracic and abdominal air sacs.13

The particle size of nebulized medications must beless than 3 µm to establish local drug levels in thelungs and air sacs.13 Particles from 3 to 7 µm gener-ally deposit in the trachea and mucosal surface of thenasal cavity.13,60 Many inexpensive commercial nebu-lizers do not produce a particle size small enough forpenetration of the lower airways. Ultrasonic nebuliz-ers are most effective in producing small particle sizeand are recommended for use in birds. The tubingand chamber of the nebulizer should be easy to cleanafter each use, and should be sterilized between birdsto avoid introduction of bacterial or fungal organismswith the nebulized solutions.

In general, most parenteral antibiotics formulatedfor intravenous use can be used for nebulization.Bactericidal antibiotics appear most successful innebulization therapy. With air sacculitis caused byan unidentified bacteria, the authors prefer to usecefotaxime (100 mg in saline) or piperacillin (100 mgin saline) for nebulization. The suggested protocol isto nebulize for ten to thirty minutes, two to fourtimes daily for five to seven days.61 Saline is pre-ferred as the nebulizing fluid. Mucolytic agentsshould be avoided due to their irritant properties.65 Ifamikacin is used, the patient should be carefullymonitored for signs of polyuria. The effectiveness oftreating mycotic air sacculitis with nebulization isnot known.13 In some cases, medications can be in-jected directly into the trachea or a diseased air sac.

Nutritional Support

Nutritional support is mandatory for the successfulrecovery of an anorectic bird. There are two mainroutes for providing nutritional support. Enteralfeeding uses the digestive tract and is the simplest,


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while parenteral feeding bypasses the digestive tractby supplying amino acids, fats and carbohydratesdirectly into the vascular system. In mammals, en-teral feeding has been shown to be comparable to orpossibly superior to parenteral feeding.70 Parenteralnutrition is in its infancy in avian medicine, but maybe necessary for birds with gastrointestinal disease.

Enteral nutritional support is generally provided incompanion and aviary birds using a tube passed intothe crop (Figure 15.5). Necessary equipment includes10 to 18 ga stainless steel feeding needles withrounded tips, rubber feeding catheters of variousdiameters, plastic catheter adapters, oral beak spec-ula and regular and catheter-tipped syringes. A “ster-ile” feeding needle or catheter should be used for eachbird to prevent the transmission of pathogenic organ-isms. Feeding needles and catheters should be

cleaned thoroughly and sterilized after each use.Raptors are usually hand-fed pieces of prey.

Parenteral medications and fluids should be admin-istered before gavage feeding. If given afterwards,there is a risk of regurgitation during restraint forthe subsequent treatments. Oral medications canoften be administered with the enteral feeding for-mula.

The crop should be palpated before each feeding todetermine if residual feeding formula remains. Birdswith ingluvitis or gastrointestinal stasis frequentlyhave slow crop emptying times. If residual food re-mains, the crop should be flushed thoroughly with awarm, dilute chlorhexidine solution. The crop mayneed flushing for several days before motility returnsto normal. “Crop bras” are sometimes used to supportslow-moving, pendulous crops and will often improvecrop emptying (see Chapter 30).

Tube-feeding is facilitated with the help of an assis-tant, but it can be done in small birds by one person.The handler holds the bird upright with the bodywrapped in a paper or cloth towel (Figure 15.6). Anoral speculum can be useful in large birds but is notusually necessary in small birds. A speculum must beused with care to prevent damage to the soft tissuesat the lateral beak commissures.

The bird’s neck is straightened vertically with thehead grasped around the mandibles. An index fingeris placed on top of the head to prevent the bird fromthrowing its head back. The second person thenpasses the tube into the left oral commissure (Figure15.6). If the tube is passed directly from the front, thebird will try to chew at the tube. In medium-sized tolarge birds, the top beak can be pushed slightly to oneside with one hand to open the beak for passage of thetube. Alternatively, the upper beak is inserted in thelower beak, preventing the bird from biting on thetube.34a

After entering the oral cavity, the tube is passeddown the esophagus on the right side of the neck intothe crop. Tube placement can be visualized by mois-tening the feathers on the right lateral neck region.The crop is palpated to check the position of the endof the tube before injecting the feeding formula. Thetotal volume that can be given depends on the size ofthe bird (Table 15.3). The neck should be kept in fullextension during feeding to discourage regurgitation.

After injection of the food, the tube is carefully re-moved to prevent reflux. The assistant continues to

FIG 15.5 Tube-feeding is frequently necessary as part of thesupportive care provided to anorectic patients that do not havegastrointestinal tract disorders that would prohibit oral alimenta-tion (eg, crop stasis, ileus). Note that this African Grey Parrot’shead is held upright and the tube is inserted from the left oralcommissure (courtesy of Kathy Quesenberry).


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hold the bird with the neck in extension until the birdis released into its enclosure. If reflux of formulaoccurs at any time during the tube-feeding process,the bird should be released immediately to allow it toclear the oral cavity on its own. Attempting to swabthe oral cavity or turning the bird upside down willcause undue stress and may increase the possibilityof aspiration.

TABLE 15.3 Suggested Volumes and Frequency for Tube Feeding Anorectic Birds

Volume Frequency

Finch 0.1 - 0.3 ml Six times/day

Parakeet 0.5 - 1.0 ml QID

Cockatiel 1.0 - 2.5 ml QID

Conure 2.5 - 5.0 ml QID

Amazon 5.0 - 8.0 ml TID

Cockatoo 8.0 - 12.0 ml BID

Macaw 10.0 - 20.0 ml BID

Most hospitalized birds are tube-fed two to four timesdaily according to their clinical condition and caloricneeds. Neonates and small birds may need to be fedmore frequently (see Chapter 30).

If the crop or upper gastrointestinal system is dys-functional (eg, crop stasis, crop burns, proventriculardilatation or ventricular impaction), a bird can beprovided enteral nutrition by injecting food directlyinto the proventriculus or lower gastrointestinaltract through an esophageal gastric tube (pharyngos-tomy tube) or duodenal catheter (see Figure 41.10).The first method involves placing a soft feeding tubeinto the esophagus at the base of the mandible,through the esophageal opening at the right cropbase and into the proventriculus. The tube is suturedin place. Cellulitis should be expected to occur at theinterface of the tube and esophagus, but generallyresolves when the tube is removed.

FIG 15.6 a) For tube-feeding or crop aspiration, the bird is held in an upright position with the neck in extension. b) The tube is passedthrough the left side of the oral cavity and down the esophagus in the right side of the pharyngeal cavity. The tip of the tube should bepalpated to ensure that it is in the crop before delivering fluids or feeding formula. 1) trachea 2) esophagus 3) crop 4) laryngeal mound 5)rima glottis and 6) tongue.


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A second method for supporting enteral alimentationwhile bypassing the crop is the placement of a duode-nal feeding catheter.17 A small Foley catheter is sur-gically placed in the proximal duodenum and exitedthrough the lower abdominal wall. The end of thetube is secured to the dorsum or intrascapular areawith tape or sutures (see Chapter 41). An easilyabsorbed liquid diet is infused into the proximalsmall intestine.1,41 The volume of liquid formula thatcan be infused at one time is small, and frequentfeedings (as often as every one to two hours) arenecessary to meet caloric requirements. Alterna-tively, food can be infused at a constant rate using aninfusion pump. The authors have used this methodin young birds for up to six days without complica-tions. Duodenal tubes are not practical for use insmall birds due to the difficulty of the surgical proce-dure and the need for a duodenal tube with a largeenough diameter to allow easy infusion of a liquidfeeding formula.

Total Parenteral NutritionParenteral alimentation involves the intravenousadministration of all essential nutrients includingamino acids, lipids, carbohydrates, vitamins, electro-lytes and minerals. Potential indications for the useof total parenteral nutrition (TPN) in birds includegastrointestinal stasis, regurgitation, some gastroin-testinal surgeries, severe head trauma that pre-cludes oral alimentation, malabsorption or maldiges-tion. In dogs, 50 to 60% of the calories are suppliedby a 20% lipid solution, and the remaining caloriesare supplied by a 50% dextrose solution.28 Daily pro-tein requirements (1.5-6 gm/kg) are met by usingamino acid supplements compounded into the TPNsolution.

Difficulties associated with parenteral nutrition inbirds include placing and maintaining a catheter, thenecessity of multiple intermittent feedings to supplycaloric requirements and potential metabolic compli-cations associated with parenteral nutrition41 (hypo-phosphatemia, hypo- or hyperkalemia, hyperglyce-mia and liver function abnormalities). Sepsis orbacteremia can occur from bacterial contamination ofthe catheter. Continuous infusion is the preferredmethod for administration of TPN, allowing for rapiddilution of the hypertonic solution, which minimizesirritation to the vascular endothelium.

The intraosseous cannula or a vascular access devicecan be used for parenteral alimentation.12 Vascularaccess devices have been used experimentally forTPN in two geese.20 The birds received the TPN

formula in four daily infusions of twenty to thirtyminutes each using an infusion pump set at 5 ml/min.Both geese showed marked hematologic changes af-ter receiving TPN, including heterophilic leukocy-tosis; increases in SGPT, AP, cholesterol and CPK;and decreases in glucose, bile acids and triglycerides.One goose died on the second day of TPN. Acute renalischemia and necrosis were cited as the cause ofdeath. Histopathologic, microbiologic and clinical pa-rameters implicated inflammation and bacteremiasecondary to Staphylococcus aureus contamination ofthe VAD. The second goose was maintained on TPNfor four days with no clinical abnormalities. Necropsyshowed minor changes in the kidneys that were notassociated with uric acid elevations.

Total parenteral nutrition administered by VAD wassuccessful when given experimentally in pigeons.12

The TPN was administered in four daily infusionsover a five-day period. Clinical changes were mildincluding weight loss, regurgitation, transient hy-perglycemia, polyuria, glucosuria and tachycardia.

Because the nutritional requirements for avian pa-tients are not known, formulation of TPN diets isprimarily extrapolated from mammalian diets andthe nutritional requirements of poultry. Enteric liq-uid diets are estimated to be 90% bioavailable, whileTPN solutions are 100% available.

Typically a 10% amino acid solutioni, a 20% lipidsolutionj and a 50% dextrose solution are used. Theamino acid solution provides 100 mg protein/ml, thelipid solution provides 2 kcal/ml, and the dextrosesolution, 1.7 kcal/ml. These three solutions can bemixed under clean conditions as a three-in-one TPNsolution.20 A 1000 ml bag of five percent dextrosesolution is connected to an IV drip set and asepticallyemptied. One day’s supply of amino acid solution isinjected through the port into the bag. The 50%dextrose solution is then added and mixed by invert-ing the bag. The lipid solution is added last. It shouldbe added and mixed slowly over a two-minute period.This mixture should be used within 24 hours andshould be stored in the refrigerator.20

Nutritional RequirementsIllness and stress cause a hypermetabolic state inanimals and humans. Release of catecholamines,glucagon and glucocorticoids increases the rate ofgluconeogenesis and glycogenolysis. When the in-crease in metabolic rate is coupled with a decreasednutritional intake, fat oxidation occurs at a maxi-mum rate, and body proteins are used as an energy


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source.28 Blood glucose concentrations are increased.Intravenous infusion of isotonic glucose has littlesparing effect on body proteins, and may actually bedetrimental by increasing the release of insulin.28

The antilipolytic action of insulin may decrease theuse of fat stores and increase body protein break-down.

Protein demand is high during periods of hyper-metabolism. Proteins are necessary for tissue repair,white and red blood cell production, maintenance ofblood proteins (albumin, fibrinogen, antibodies) andenzyme production. During periods of high demand,the body uses fatty acids preferentially for energy tospare protein. In the management of human pa-tients, more than 40% of the total kilocalories inmany enteral diets are derived from fatty acids.

The size, weight, reproductive status and season allaffect the daily caloric needs of birds. The basalmetabolic rate (BMR) is the minimum amount ofenergy necessary for daily maintenance. An estimateof the BMR for birds can be made based on metabolicscaling:58

BMR = K(WKG 0.75)Passerine birds K = 129

Non-passerine birds K = 78

The K factor is a theoretical constant for kcal usedduring 24 hours for various species of birds, mam-mals and reptiles. The maintenance energy require-ment (MER) is the BMR plus the additional energyneeded for normal physical activity, digestion andabsorption. The MER for adult hospitalized animalsis approximately 25 percent above the BMR.28 Inpasserine birds, MER varies from 1.3 to 7.2 times theBMR, depending on the energy needed for activityand thermoregulation during different times of theyear.72 With growth, stress or disease, animals are ina hypermetabolic state with daily energy needs thatsurpass maintenance. The amount of increased de-mand depends on the type of injury or stress andvaries from one to three times the daily maintenancerequirement (Table 15.4).

TABLE 15.4 Adjustments to Maintenance for Stress (as multiples of MER)41

Starvation 0.5 - 0.7Elective Surgery 1.0 - 1.2Mild Trauma 1.0 - 1.2Severe Trauma 1.1 - 2.0Growth 1.5 - 3.0Sepsis 1.2 - 1.5Burns 1.2 - 2.0Head Injuries 1.0 - 2.0

Although not exact, metabolic scaling can be used toestimate the approximate daily caloric needs of birds.

Enteral Nutritional FormulasIn humans, diets used for enteral nutrition are cho-sen based on the clinical condition of the patient. Forbirds, a formula should be used that supplies basicprotein, fat and carbohydrates, and is adequate inmeeting the energy requirements of the patient.

Commercial enteral nutritional formulas marketedfor humans are widely available. These diets areusually liquid formulations sold in 250 ml contain-ers. The diets vary in caloric density, protein, fat andcarbohydrate content and osmolality (Table 15.5).Formulas vary from meal replacement formulas,which require some digestion, to monomeric diets,which require little or no digestion. Almost all dietsare lactose-free and are approximately 95 percentdigestible. These diets have been successfully usedfor routine nutritional support in sick birds via anenteral route. Knowing the exact caloric density permillimeter is convenient for calculating daily main-tenance requirements. Formulas range from lessthan 1.0 to 2.0 kcal/ml. With a calorie-dense formula(2.0 kcal/ml), the total volume of liquid can be givenin two to four feedings per day. Maintaining adequatehydration is important in birds when using calorie-dense formulas. Once opened, enteral formulas canbe refrigerated for two to three days. For feedings,the formulas can be heated gently, such as in a syr-inge under hot running water.

CL INICAL APPL ICATIONSExample of Metabolic Scaling to Estimate Approximate DailyCaloric Needs of Birds*An Amazon parrot weighing 350 grams is presented for septi-cemia secondary to bacterial enteritis. Estimating MER as 1.5times BMR, the daily caloric needs can be estimated as:

BMR = 78(0.350.75) or 35 kcal/day

1.5 x 35 kcal/day = 53 kcal/day approximate MER

1.2 x 53 kcal/day = 63.6 kcal/day increase for sepsis

If the energy content of the feeding formula is known, the dailycalorie needs are divided by the calories per ml of formula tocalculate the total volume of formula needed daily. For example,using a formula that is 1.5 kcal/ml, the total volume of formulaneeded per day for the Amazon is:

63.6 kcal/day 1.5 kcal/ml = 42.4 ml needed daily

*See Appendix for instructions on using this formula.


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TABLE 15.5 Commercial Enteral Products: Nutrients per 100 kcal* Energy41

Product Protein (g) Fat (g) Carbos (g) kcal/ml

Isocalk 3.4 4.4 13.3 1.0

Isocal HCNk 3.8 5.1 10.0 2.0

Traumacalk 5.5 4.5 9.5 1.5

Pulmocarel 4.2 6.1 7.0 1.5

Ensure Plusl 3.6 3.5 13.0 1.5

* kcal = calories

Formula may curdle in the crop of birds with inglu-vitis and gastrointestinal stasis, probably because ofchanges in the pH of the crop. Flushing the crop withwarm water while gently massaging the crop willcause the curdled formula to break apart, allowingaspiration and removal. Multiple feedings of smallamounts of an isotonic or diluted formula should begiven until the crop motility is normal.

Commercial enteral formulas marketed for use inbirds are available (Figure 15.7). These diets areeither dry powders or liquids. They are consistent innutritional content, easy to prepare and use andrelatively low in cost. In general, these diets arerelatively high in carbohydrate content when com-pared to human products. Some products are low incalorie content. Powdered products can curdle orsludge in the crop, especially if an inadequateamount of water is used for mixing.

Some veterinarians prefer to blend their own feedingformulas. Combinations of monkey chow, baby ce-real, strained baby vegetables, vitamin and mineralsupplements and water are used. Plant enzymes aresometimes added to improve digestibility (see Chap-ter 18). Homemade formulas may work but have thedisadvantage when compared to commercial prod-ucts of varying consistency and nutritional and ca-loric content. Formulas based on baby cereal areusually high in carbohydrates and low in fat andprotein. Many homemade formulas are too high inwater content and provide insufficient levels of en-ergy. Following the bird’s weight on a daily basis (ingrams) is the best evaluation of enteral feeding.

Oxygen Therapy

An oxygen enclosure is highly recommended asstandard equipment in an avian practice (Figure15.8). There are several commercially available en-closures made specifically for use in birds. Most aredesigned as incubators with controls for heat andmonitors for humidity. Human infant incubatorswith oxygen input ports can be adapted for use inbirds. Oxygen levels within the enclosure can bemonitored with an oxygen analyzer. Analyzersm areavailable with accuracy to within two percent. Ad-ministration of oxygen by face mask is effective forshort-term treatment if an oxygen enclosure is notavailable, or during restraint while treatments ordiagnostic tests are performed. If there is upper air-way obstruction, oxygen can be infused through anair sac tube.

The actual benefits of oxygen supplementation inbirds are unknown. Birds have a unique and efficient

FIG 15.7 Commercially available enteral nutritional products aresuperior to homemade formulas because they provide consistentnutritional and caloric content. Feeding needles can be used todeliver these products (courtesy of Kathy Quesenberry).

FIG 15.8 An oxygen enclosure should be standard equipment inany avian hospital (courtesy of Kathy Quesenberry).


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respiratory system and may respond to oxygen sup-plementation differently than do mammals. Clini-cally, dyspneic birds appear to stabilize when placedin an oxygen enclosure and maintained at 40 to 50%oxygen concentration. Oxygen therapy is potentiallytoxic in mammals if given for prolonged periods athigh concentrations. Oxygen can be supplemented insmall animals at levels up to 100% for less than 12hours without complications.65 Canaries and budg-erigars given continuous supplemental oxygen atconcentrations of 82 to 100% and 68 to 93%, respec-tively, showed signs of lethargy, anorexia, respiratorydistress and death after three to eight days.62

Pathologic changes in the lungs included pulmonarycongestion, histiocytic infiltration into the bronchiand deposition of proteinaceous material. Changeswere consistent with those seen in mammals withoxygen toxicity.

Oxygen delivery to the tissues is dependent on ade-quate perfusion. Birds that are severely anemic or incirculatory shock need adequate volume expansionand red blood cell replacement for improved tissueoxygenation to occur.

Air Sac Tube PlacementPlacement of an air sac tube is beneficial in birdswith tracheal obstructions, or when surgery of thehead is necessary. In companion birds the tube isnormally placed in the caudal thoracic or abdominalair sac, allowing direct air exchange through the tubeinto the air sac. Following tube placement, dyspneastops almost instantaneously in birds with upperairway obstruction. An air sac tube may also improverespiration in birds with air sacculitis, although theimprovement in breathing is usually less dramatic(Figure 15.9).

An alternative site for air sac cannulation used inraptors is the interclavicular air sac.43 In a studywith Peking Ducks, there were no changes in heartrate, mean arterial blood pressure, PaO2 or PaCO2

when the clavicular air sacs were cannulated (seeChapter 39).47 There were significant increases in thetidal volume and minute ventilation when comparedto control birds. These increases may have resultedfrom a decrease in effective ventilation or an increasein respiratory dead space.

A shortened endotracheal tube, trimmed rubber feed-ing tube or plastic tubing from an IV extension setcan be used for an air sac tube.54 The diameter andlength of the tube depend on the size of the bird. Thetube can be placed in the lateral flank area in the

same anatomic location as for lateral laparoscopy, orcaudal to the last rib with the femur pulled forward(Figure 15.10). The bird is placed in lateral recum-bency, prepped with a surgical scrub and a smallincision is made in the skin. Mosquito forceps areused to bluntly penetrate the muscle wall and enterthe air sac. The end of the tube is inserted into theair sac between the opened jaws of the mosquitoforceps. If the tube is patent, condensation will ap-pear on a glass slide held over the end of the tube.Tape is placed around the tube in a “butterfly” fash-ion and sutured to the skin, or a fingertrap suturetechnique is used. If a shortened endotracheal tubeis used, the cuff can be slightly inflated just insidethe abdominal wall to form a secure seal.

If placed correctly, the bird will immediately beginbreathing through the tube. If anesthetized, the bird

CL INICAL APPL ICATIONSAir sac tubes can be used to:

Alleviate dyspnea secondary to URD

Deliver anesthesia for evaluation or surgery of the head ortrachea

Provide an immediate airway following apnea

Deliver nebulized medications to a specific air sac

FIG 15.9 A Sulphur-crested Cockatoo was presented with an acuteonset of severe dyspnea. The bird was in excellent overall condi-tion. The bird was anesthetized with isoflurane and an air sac tubewas inserted in the abdominal air sac. The bird began to breathenormally within two to three minutes of inserting the air sac tube.An Ayres T-piece was connected to the air sac tube and the birdwas maintained on 1.5% isoflurane delivered into the air sacs. Asmall plastic ball was identified in the rostral part of the tracheaby endoscopy. A needle was passed through the trachea distal tothe ball to prevent it from descending further down the trachea.The ball was removed by holding the bird upside down and usingsuction.


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FIG 15.10 Placement of a tube in the abdominal air sac can be used to provide oxygen or isoflurane anesthesia. a) The tube is placed bymaking a small skin incision in the area of the sternal notch. b) A pair of hemostats is passed through the body musculature and the airsac tube is inserted between the jaws of the hemostats. c,d) A cuffed endotracheal tube can be sutured to the body wall if the tube willremain in place for several days.

1) left femur

2) abdominal air sac

3) eighth rib

4) lung

5) abdominal wall


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will become light unless the end of the tube is oc-cluded or attached to the anesthesia machine. Theair sac tube can be left in place for three to five days.The effect of direct exchange of room air into the airsac and the potential for introduction of contami-nants and infectious organisms into the cannulatedair sac are unknown.

An air sac tube allows many treatment techniques tobe performed that would otherwise be impossible ina dyspneic bird. Liquid medications can be instilleddirectly into the trachea for the treatment of bact-erial or fungal tracheitis. The bird can be anesthe-tized through the tube for surgery or endoscopy of thetrachea or head, and the tube can be used for positivepressure ventilation or resuscitation. Birds can benebulized with the air sac tube in place, possiblyincreasing the concentration of antimicrobials in theair sacs. If apnea occurs, a needle can be used in placeof a tube for providing a rapid source of oxygen.

Heat

A warm ambient environment is necessary for birdsthat are debilitated or in shock. Many commercialenclosures and incubators are available with floor orceiling heating elements, side heating consoles orradiant heat systems. Floor heating elements mayoccasionally cause hyperthermia when debilitatedbirds are forced to stand or lie on the enclosure flooror in direct contact with the heating surface. Alterna-tively, heat can be provided by a hot water bottle orwell insulated heating pad (preferably water). Birdsreceiving supplemental heat from any source otherthan a commercial incubator should be carefullymonitored to prevent burns. Small, heated roomsthat hold two to three enclosures allow birds to betreated in a temperature-stable environment, reduc-ing the stress associated with being removed from awarm incubator to a cooler treatment area. It shouldbe noted that none of the commercially availableincubators with forced air heating systems can beproperly sterilized with any procedure that does notinvolve the generation of formalin gas.

Enclosures should be equipped with thermometers tomonitor ambient temperature. Many commercial en-closures also have humidity sensors. Ambient tem-perature for adult birds should be 85°F and humidityshould be approximately 70%. Unfeathered babybirds less than ten days old need an ambient tem-perature of 94°F.25 Older chicks can be maintained at90°F. Birds in heated enclosures should be monitored

for hyperthermia, which is clinically suggested bypanting and holding the wings away from the body.

Housing

Many sick birds are too weak to perch. These birdsshould be placed in a smooth-sided enclosure or incu-bator without perches. Thick paper or non-woventowels can be used on the bottom of the enclosure.Many sick birds will not eat unless food and waterare easily accessible. Seeds, fruits and vegetables canbe spread around the bird to encourage eating. If thebird is still perching, food and water containersshould be placed next to the perches to encouragefood consumption. Millet spray is an attractive fooditem for many smaller species.

Although abrupt diet changes should not be at-tempted while the bird is sick, offering the bird abalanced diet in addition to any food it is accustomedto eating is appropriate, and may offer therapeuticbenefits because of improved nutrient value. Foodand water should be removed from the enclosure ofbirds that are seizuring, obtunded or post-anestheticto decrease the danger of aspiration or drowning.

Birds with leg fractures or paralysis are best main-tained in a wire enclosure on thick cage paper ortoweling. These birds will grasp the wire siding withtheir beak to steady themselves. If perches are pro-vided, they should be close to the enclosure floor toprevent injuries.

Emergency Problems

Cardiovascular System

Bleeding and AnemiaThe emergency clinician is often presented withbleeding birds and sick birds that are anemic. Ane-mia in birds may be caused by blood loss, decreasedred blood cell production and increased red blood celldestruction. As in mammals, anemias can be classi-fied as regenerative or non-regenerative.

The most common cause of blood loss in birds istrauma (Figure 15.11). Other causes include gastro-intestinal (GI) bleeding, genitourinary bleeding,hemolysis and idiopathic hemorrhage. Hemato-chezia and melena may occur from enteritis, gastro-


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intestinal ulcers, coagulopathies, liver disease andGI foreign bodies. Cloacal bleeding may be caused bycloacal papillomas, cloacitis, egg laying, or cloacal oruterine prolapse. Heavy metal toxicity can causehemolysis, which may result in dramatic hemoglo-binuria in some birds, especially Amazon parrots.Conures may present for a sudden onset of weakness,ataxia, epistaxis, bloody regurgitation, bleeding fromthe oral cavity, hematochezia, hemorrhagic conjunc-tivitis or muscle petechiation.

Anemias resulting from decreased red blood cell pro-duction are common in birds, possibly because of therelatively short life-span (28 to 45 days) of the avianerythrocyte.22 “Depression anemias” are usuallycaused by chronic infectious, toxic or nutritional dis-ease. A rapidly fatal non-regenerative anemia seen intwo- to four-month-old African Grey Parrots is sus-pected to be of viral etiology. Some birds with thisproblem have been shown to have polyomavirus orPBFD virus antigens in the bone marrow.

Diagnosis of anemia is based on clinical signs anddocumentation of a decreased PCV. Weakness is themost common clinical sign. Severely anemic birdsmay have a dull, almost dazed demeanor. Tachypneaand tachycardia may also be present. On physicalexamination, pallor of mucous membranes is evidentin the oral cavity, palpebral conjunctiva and cloaca.

CBC and reticulocyte count, serum or plasma bio-chemistry analysis, blood heavy metal concentrationand whole body radiographs should be considered incases of anemia of unknown origin. Further testingmight include chlamydia screening and a bone mar-row aspirate. If an intraosseous cannula will be nec-essary for stabilizing the patient, a bone marrowsample can be obtained through the cannula at thetime of placement. If the mucous membranes arepale, the PCV should be determined before drawingmore blood. If the PCV is below 15%, further bloodcollection is inadvisable. It should be noted that thevolume of serum or plasma relative to the volume ofwhole blood will be increased due to the anemia; theminimum amount of blood necessary to perform thedesired diagnostic tests should be drawn.

If the bird is actively bleeding on presentation, local-ization of hemorrhage and hemostasis are the firstpriorities. Developing feathers are called “bloodfeathers” because of the rich vascular supply withinthe shaft. When one of these feathers is broken, itmay continue to bleed until it is removed from itsfollicle. For removal, the base of the damaged feather

is identified by parting the surrounding feathers.The base is grasped firmly with hemostats, and thefeather is removed from its follicle by gently placingopposing pressure on the structure around thefeather base (Figure 15.12). If any bleeding occursfrom the dermis, it can be controlled by applyingpressure to the area or packing the follicle withsurgical gel. Chemical or radiosurgical cauteryo

should not be used inside the feather follicle becausethe subsequent inflammation and tissue damage cancause abnormal feather regrowth, resulting in theformation of feather cysts.

For home first aid, the client can be advised to washany blood away with hydrogen peroxide, apply corn-starch or flour to the bleeding area and place the birdin a dark area until it can be presented to the clini-cian for evaluation. Bleeding from a nail can be ar-rested using ferric subsulfate, silver nitrate or bipo-lar radiosurgery. Application of bar soap or heat froma red-hot item can also serve as first aid measures.

FIG 15.11 A mature female Red-tailed Hawk was presented afterbeing found in a forest dragging a steel jaw trap. All of the softtissues surrounding the metatarsus were destroyed. The metatar-sus was black. The bird was euthanatized. Steel jaw traps areillegal in many states but are still used by poachers and individualsunconcerned with the inhumane destruction of free-ranging ani-mals.


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Persistent bleeding from soft tissue wounds is lesscommon. If such bleeding occurs, it can be controlledby applying pressure to the area or through the useof bipolar radiosurgery. Surgical tissue adhesiveb isoften useful (Figure 15.13). Hemorrhage from oraland tongue lacerations may be difficult to control.Complete evaluation and suturing of these lacera-tions usually require general anesthesia.

The extent of blood loss can be gauged by the historyor by the amount of blood present in the carrier. Thecapacity of birds to tolerate acute blood loss is oftenunderestimated. In general, flighted birds tolerateblood loss better than mammals and non-flightedbirds. Blood volume in birds averages ten percent ofbody weight. A healthy bird can lose as much as 30%of blood volume (about 3 ml/100 grams of bodyweight) with minimal clinical problems.44 Because it

takes roughly 24 hours following hemorrhage for thePCV to equilibrate, measurement of the PCV twodays after the onset of blood loss is most useful as adiagnostic and prognostic indicator.

Nonspecific treatment for blood loss includes volumereplacement by subcutaneous or intravenous fluids,and the administration of iron dextran and B vita-mins (see Chapter 18). The need for hospitalizationand further supportive care depends on physical ex-amination findings. Birds that are weak and in shockwill require more aggressive therapy. Birds on anall-seed diet can be assumed to be nutritionally defi-cient and will benefit from an injection of vitamin K1.

In birds with idiopathic hemorrhage, such as inconure bleeding syndrome, injectable vitamin K1, vi-tamin D3, calcium and antibiotics are indicated. Theetiology of conure bleeding syndrome is unknown,but it is possible that a dietary lack of vitamin K,calcium and other nutrients may alter normal clot-ting mechanisms.51,55 If hemoglobinuria is present,treatment should be initiated with calcium disodiumedetate (CaEDTA) for possible heavy metal toxicity(see Chapter 37). If clinical signs are being caused byheavy metal toxicity, there will usually be clinicalimprovement within six hours of initiating CaEDTAtherapy.

The benefits of blood transfusions in birds are contro-versial. In pigeons that lost 70% of blood volume, it

FIG 15.13 Careful application of tissue adhesives can be used tocontrol bleeding of the beak or nails. Glue applied to the beak mustnot be allowed to run into the mouth or onto the eyelids.

FIG 15.12 Primary and secondary pin feathers have a substantialblood supply that arises at the base of the feather shaft where it isattached to the periosteum. Damaged pin feathers can result insubstantial blood loss. Correctly removing the feather will allowthe nutrient artery to collapse and will stop the bleeding. Toremove a pin feather, the base of the feather is grasped with a pairof hemostats as close as possible to the skin edge. The skin issupported by applying gentle, opposing force around the feather


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was determined that fluid replacement with LRSwas more effective in resolving anemia than irondextran, homologous blood transfusions or heterolo-gous blood transfusions. All study birds had a normalPCV within six days following acute blood loss. Het-erologous transfusions from chickens were not aneffective treatment, but the authors concluded that ahomologous blood transfusion might be useful inbirds with a PCV <20%.6 A similar controlled study isneeded to evaluate blood transfusions in psittacinebirds. Until a controlled study is performed, it isprobably valid to assume that homologous bloodtransfusions are preferable to heterologous, and thatin most instances, a blood transfusion will notgreatly increase the survival rate in acute blood loss.However, in the authors’ experience, even heterolo-gous blood transfusions appear to be clinically bene-ficial to birds suffering from chronic anemia. The goalof the transfusion is to stabilize the patient whilediagnostic tests can be used to determine the etio-logic agent of the anemia. A transfusion volume ofroughly 10 to 20% of calculated blood volume is ideal.A rough cross-match can be performed by mixing redblood cells from the donor with serum from the recipi-ent; the absence of gross agglutination or hemolysissuggests compatibility.

ShockThe state of shock is difficult to determine in theavian patient. Clinical signs include weakness, pal-lor and poor perfusion of peripheral vessels. Vascularperfusion can be estimated by occluding the ulnarvein proximally on the medial surface of the wing andevaluating turgescence and filling time.1 Decreasedturgor and a filling time greater than 0.5 seconds areindications of reduced circulatory volume. Septicshock is a possibility in debilitated birds, and isclinically recognized as severe depression, particu-larly in birds with known exposure to infectious dis-eases.

Therapy for shock includes administration of fluidsto expand the circulating blood volume and rapidlyacting corticosteroids. If possible, corticosteroids andfluids should be administered intravenously or in-traosseously. Intramuscular corticosteroids and sub-cutaneous fluids are beneficial but take more time toenter the circulation. In cases of shock, a state ofmetabolic acidosis may be present, and bicarbonatereplacement therapy should be considered. Paren-teral bacteriocidal antibiotics are given if bacterialinfections are suspected.

Cardiac FailureThe field of avian cardiology is in its infancy, andcardiac failure is rarely diagnosed antemortem. Suspi-cious clinical signs include weakness, anorexia, tachyp-nea, dyspnea, coughing and abdominal distension dueto hepatomegaly and ascites. The diagnosis is sug-gested by finding an arrhythmia or murmur on auscul-tation, and by radiographic changes including cardi-omegaly, hepatomegaly and ascites (Figure 15.14). Asingle IM dose of furosemide, low-dose subcutaneousfluids and an oxygen-rich environment are indicated.Electrocardiography and ultrasonography are used toconfirm cardiac disease and guide the selection of othercardiac medications (see Chapter 27).35,48

Cardiopulmonary Resuscitation (CPR)Avian CPR follows the same “ABC’s” as mammalianCPR: Airway, Breathing and Circulation. In a birdthat has stopped breathing, an airway must be estab-lished by placing an endotracheal or air sac tube. Toavoid the danger of zoonotic disease, it is preferableto ventilate the bird in this fashion; alternatively,mouth-to-mouth respirations can be given by cup-ping the mouth over the bird’s nares and beak open-ing. Positive pressure ventilation should occur onceevery four to five seconds. Once ventilation has beenstarted, the heart beat or peripheral pulse should bedetermined. If neither is present, the heart should bemassaged by firm and rapid compression of the ster-num. Epinephrine and doxapram are given as neces-sary. The intratracheal, intracardiac or intraosseousroutes (even spray into the thoracic cavity if open) foremergency drug administration should be consideredwhen peripheral vascular access is not possible.24

Cardiopulmonary resuscitation should always be at-tempted in previously healthy birds that have col-lapsed; however, CPR is rarely successful in birdsthat are debilitated from long-standing, chronic dis-ease.

Gastrointestinal System

Crop Burns and InjuriesThermal burns of the crop are seen in hand-fed neo-nates, particularly psittacine birds. The most com-mon cause is the occurence of “hot spots” in poorlymixed microwaved formulas. Birds will accept theoverheated formula without showing discontent. Afew hours after feeding, an erythematous area of skinis evident overlying the crop, generally on the rightventral portion. If the bird has feathers in this area,the burn is often not noted unless the crop and skin


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necrose, leaving a fistula from which formula drainsout onto the breast feathers (see Color 30).

The presence of a fistula is alarming to most owners;however, it is a true emergency only if the fistula isso large that all formula drains out of the crop,leaving the bird in danger of dehydration and starva-tion. The frequency of feedings may have to be in-creased in the interim in order to replace the formulalost through the fistula. If the burn is discovered soonafter it occurs, the crop area should be monitoreddaily. The use of anti-inflammatories (eg, corticos-teroids) represents more of a risk than a benefit inyoung birds (see Chapter 41).24 Some periesophagealburns, lacerations and other injuries may not resultin fistula formation and are recognized clinically ascrop stasis. In some cases, the feeding instrumentmay have punctured the crop, and the food is depos-ited between the skin and the crop wall. This is a trueemergency because the bird can suddenly becometoxic, exhibit massive edema and die.

Gastrointestinal StasisGastrointestinal stasis is a common problem in pedi-atric medicine. Multiple factors that may affect GImotility in young birds include infectious disease,poor sanitation, low environmental temperature, low

formula temperature and low humidity. Physical ob-structions are usually caused by foreign body inges-tion (bedding is a common culprit) or accidental in-gestion of a feeding tube. Causes of GI stasis in adultbirds include gastroenteritis (leading to ileus),neuropathic gastric dilatation, heavy metal toxicityand obstruction (see Chapter 19).

Delayed crop emptying is the most common present-ing sign of GI stasis. Regurgitation or vomiting mayoccur also. Fecal output is reduced. If allowed topersist, the bird becomes dehydrated, loses weightand may become septic. Chronic cases in debilitatedbirds can be difficult to manage and treat effectively,and the client should be advised that therapy may belengthy and that the prognosis is poor.

Physical examination begins with an assessment ofhydration status and thorough palpation of the cropfor the presence of foreign bodies or inspissated foodmaterial. Some crop foreign bodies, particularly lin-ear ones, can be removed by carefully manipulatingthem back up the cranial esophagus and into theoropharynx, where they are visualized and graspedwith forceps. Removal of other foreign objects andinspissated food material is most easily accomplishedvia ingluviotomy (see Figure 41.13). The bird is anes-

FIG 15.14 A one-year-old Umbrella Cockatoo was presented for emaciation (409 g)and depression. The bird had severed an electric cord the day before presentationand was having problems swallowing. Physical examination findings included harshrespiratory sounds (lung area) and dull “sunken” eyes. Abnormal clinical pathologyfindings included PCV=30, LDH=1400 and AST=850. Radiographic lesions includedcardiomegaly (h), gaseous distension of the gastrointestinal tract (ileus) and enlargedradiodense kidneys. Note the gaseous distension of the proventriculus (arrows). Theenlarged radiodense kidneys are suggestive of severe dehydration (consistent withphysical examination findings), but microcardia is more characteristic of dehydra-tion than cardiomegaly. The bird did not respond to emergency therapy. Histopa-thology findings included severe hepatocellular necrosis and pulmonary hemor-rhage.


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thetized with isoflurane and intubated to reduce thedanger of aspiration. A small incision is made overthe left lateral pendulous crop to ensure that theincision is not damaged should the bird require tube-feeding. The incision is closed in two layers using a6-0 absorbable suture. Postoperative feedings shouldbe small and frequent, beginning with clear liquidsand gradually increasing the strength and amount offormula over the next 24 to 48 hours until a normalfeeding schedule has been resumed.

If a crop foreign body cannot be palpated, food andwater should be withheld until the crop is empty orthe crop can be drained by the clinician. Usually it isdifficult to empty the crop via gavage tube becausecrop contents tend to become thickened when thecrop is static. Some clinicians hold the bird upsidedown and express the crop contents.50 The authorsbelieve that this technique in unanesthetized pa-tients puts the bird in risk of aspiration, and thateven when used in anesthetized patients, a fingershould be placed over the choanal slit during theprocedure to prevent reflux from entering the nasalpassages. Another technique is percutaneous aspira-tion of the crop using an 18 to 22 ga needle.24 Flush-ing the crop with 0.05% chlorhexidine solution isoften beneficial. This can be done two to four timesdaily if the bird can tolerate the handling. Afterflushing, a small amount of LRS, followed in threehours with dilute formula or Isocal,k should be ad-ministered by gavage tube.

Radiographs and a barium series are indicated ifimpaction or extraluminal obstruction is suspected,particularly in adult birds. Before the series is begun,the crop contents should be removed and the anes-thetized bird should be held upright until the esopha-gus can be packed with moist gauze. A finger placedover the cranial esophagus will help prevent refluxfrom entering the pharyngeal area.

A minimum database should include cytology of thecrop contents and fecal wet mounts (see Chapter 10).Samples can be collected by crop lavage or by passinga flexible swab directly into the crop. Culture andsensitivity of the crop contents and feces are indi-cated if bacterial infection is suspected. An in-houseblood glucose determination is important if the birdis weak.

In birds with GI stasis, restoring and maintaininghydration with subcutaneous, intravenous or intra-osseous fluids is important, and should be consideredprior to performing surgery or other stressful proce-

dures. Parenteral antibiotics and metoclopramiden

are often indicated (see Chapter 18). Oral medica-tions are mostly ineffective because of slow passageinto the intestinal tract. Oral aminoglycosides, how-ever, may be beneficial in cases of bacterial over-growth because they act locally with minimal absorp-tion or side-effects. Parenteral feeding or placementof a duodenal feeding tube should be considered incritically ill birds (see Chapter 41).

Budgerigars with goiter often present with crop sta-sis and a history of regurgitation due to pressure ofthe enlarged thyroid glands on the caudal esophagus.These birds may also have a squeaky voice or anaudible click with each respiration; tachypnea andtail-bob may be present. Diagnosis of goiter is basedon clinical signs and history of an iodine-deficientdiet. These birds should be hospitalized for paren-teral fluids, steroids, antibiotics and iodine therapy.In mild cases, crop motility may be restored withoutthe need for emptying and flushing the crop by gav-age tube. Occasionally a bird may not respond tostandard therapy, and thyroid gland neoplasiashould be considered in these cases.

Regurgitation and VomitingThe distinction between regurgitation and vomitingin birds is often difficult to make clinically and, forthe purposes of this section, the term regurgitationwill be used.

Regurgitation to a “mate” (often the owner) or mirroris a normal part of breeding behavior; this is seenmost commonly in budgerigars and cockatiels but canoccur in any psittacine bird. A clinical history thatincludes intermittent regurgitation when the bird isbeing handled or talked to will help differentiate thisnormal behavior from a pathologic problem. Pa-thologic regurgitation in birds is caused by primaryGI problems, metabolic problems and toxicities thatinduce nausea. Primary GI problems include infec-tion (bacterial, viral, fungal and parasitic) and bothintraluminal and extraluminal obstruction. Metabo-lic problems include hepatic and renal disease (seeChapter 19). Toxins that may cause vomiting includeingestion of some plants, pesticides and heavy metalssuch as lead or zinc. Some birds will regurgitate fromstress or from motion sickness (such as during a cartrip). Iatrogenic regurgitation may occur when thecrop is over-distended with gavage formula and dur-ing recovery from chemical sedation or anesthesia.

Birds that are regurgitating will make a head-bob-bing and neck-stretching type of motion. If the owner


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does not observe or recognize this characteristic mo-tion, a sign of regurgitation is finding food caked onthe head feathers, giving the bird a spiky, “punk-hairdo” appearance (see Figure 19.7). A bird willoften shake its head when regurgitating, depositingthe regurgitus about the face and head. The birdshould be evaluated for hydration, and the crop andabdomen should be palpated for distension or thepresence of a foreign body or a mass. Goiter is themost common pathologic cause of regurgitation inbudgerigars over two years of age. Bloody regurgita-tion may be seen in conure bleeding syndrome.

Initial diagnostic testing should include swabbing orflushing the crop for a wet mount, cytology, Gram’sstain and culture. Fecal examination by wet mountand Gram’s stain is often informative also. Otherdiagnostic tests to consider include a CBC, biochem-istry profile and blood heavy metal concentration.Whole body radiographs, a routine barium series, ora double contrast study of the upper GI tract may beuseful (see Chapter 12).

Initial stabilization of the regurgitating patient in-volves parenteral fluid therapy, removal of foreignbodies or toxins, specific toxin antidotes and appro-priate antimicrobials if bacterial or fungal infectionsare suspected. Flushing the crop with 0.05% chlor-hexidine reduces local bacterial levels in cases ofingluvitis.

Severe Diarrhea, Hematochezia and MelenaDiarrhea in birds is clinically recognized by un-formed feces, often in association with an increase inthe fluid portion of the dropping (see Color 8). Stoolsmay “normally” be loose from stress, excitement,over-consumption of dairy products and ingestion offoods with a high water content (vegetables andfruits). Pathologic diarrhea usually results from bac-terial, viral, fungal, chlamydial or parasitic gastroen-teritis. The presence of a foreign body in the GI tractcan also cause diarrhea. Pancreatic or liver diseaseand ingestion of some toxins may cause diarrhea.The differential diagnosis list for the emergency pa-tient with diarrhea includes gram-negative enteritis,hep-atopathy, chlamydial infection and heavy metaltoxicity.

Physical examination of the bird with diarrheashould begin with careful evaluation of the hydrationstatus and gross evaluation of droppings for evidenceof blood, mucus, undigested food, plant material orgravel. Melena may be noted with problems of theupper GI tract (enteritis, foreign bodies, parasites,

ulcers). Hematochezia may be present with diseaseof the colon or cloaca. Cytology or a dip stick for fecaloccult blood should always be used to document GIbleeding before aggressive and unnecessary therapyis instigated. The cloacal mucosa can be examined byprolapsing it gently with a well lubricated cottonswab (Figure 15.15). The presence of yellow or greenurates suggests involvement of the liver. Brown,pink, red or rust-colored urates are seen most com-monly with acute heavy metal toxicity, particularlyin Amazon parrots (see Color 8). Birds consumingheavily pigmented fruits (eg, blueberries, blackber-ries) may have dark feces that mimics melena orhematochezia (see Color 8).

The database for diarrhea includes fecal examinationby wet mount, Gram’s stain and culture. Cytology forGiardia sp. , Trichomonas sp. or other protozoashould be considered. Other valuable diagnostic testsinclude a CBC, biochemistry profile, radiographs,blood heavy metal concentration and screening forchlamydia.

Parenteral fluids should be administered to meetmaintenance levels and replace estimated fluid vol-ume lost to diarrhea. Debilitated birds may benefitfrom intravenous or intraosseous fluids and one doseof rapidly acting corticosteroids. Parenteral admini-stration of a bacteriocidal antibiotic with a broadgram-negative spectrum is indicated because bacter-ial enteritis is common with diarrhea either as aprimary cause or as a secondary problem.

Cloacal ProlapseProlapse of the cloacal mucosa is associated withmasses within the cloaca, neurogenic problems orconditions causing tenesmus (eg, enteritis, cloacitisor egg-binding). Idiopathic prolapses are seen also.

A prolapsed cloaca may not be immediately apparentto the owner unless the bird is seen self-traumatizingthe area or there is blood on the droppings. Thehistory should include questions about diarrhea,straining or previous egg laying. Abdominal palpa-tion for a mass and checking for prolapse of theureters or uterus should be a priority during thephysical examination. Cloacal tumors, such as ade-nocarcinomas, tend to be single and discrete. Anirregular, “raspberry-like” appearance of the mucosasuggests cloacal papillomatosis (see Color 19).

Diagnostics and treatment are best performed withthe bird relaxed under isoflurane anesthesia. Fecalretention is a problem with long-standing prolapsesand with neurogenic etiologies (see Color 19). Man-


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ual massage of the caudal abdominal and cloacalregions promotes fecal evacuation. Parenteral fluidtherapy and treatment for septic shock should beused in these cases.

A complete examination of the cloacal area must beperformed. In larger birds, a vaginal speculum andstrong light source permit examination deep into thecloacal region. Diagnostic tests to consider includefecal wet mount, Gram’s stain, culture and radio-graphs. If cloacal papillomatosis is suspected, tissueexcision with biopsy is necessary to confirm the diag-nosis. A prolapsed cloaca caused by papillomas doesnot require a purse-string suture preoperatively. Infact, purse-string sutures in birds with cloacal papil-lomas may result in blockage of the cloacal openingand are thus contraindicated. Solitary tumors shouldbe biopsied by excision if possible.

Prolapsed mucosa should be protected from damageand desiccation. The tissues should be flushed withsaline and covered with a sterile lubricating jelly orointment. The need for a retention suture will varydepending on the individual bird and the clinician’spreferences. Retention sutures may complicate theprolapse by exacerbating straining and should beavoided if at all possible. If a retention suture isplaced, it must not interfere with evacuation of thecloaca.24 A cloacapexy may be necessary in some birds

that chronically prolapse (see Chap-ter 41). It is important to treat anypossible underlying cause of pro-lapse such as hypocalcemia or othernutritional or metabolic problems.

Liver DiseaseAs in mammals, liver disease is oftendifficult to diagnose and characterizein birds (see Chapter 20). Clinicalsigns of hepatitis are often nonspe-cific, including lethargy, inappe-tence, polyuria, polydipsia, diarrheaand ascites. Birds with ascites areoften tachypneic or dyspneic. Thepresence of yellow or green urates isan indicator of probable liver disease(see Color 8). On physical examina-tion, an enlarged liver may be palpa-ble or, particularly in passerinebirds, may be visible through theskin.

The basic database for suspectedhepatitis includes a complete blood

count, serum biochemistry profile, bile acids, fecalGram’s stain, fecal culture, cytology of the abdominalfluid, whole body radiographs and chlamydial test-ing.

While laboratory tests are pending, treatment forsuspected liver disease includes basic supportivecare, broad-spectrum antibiotics, oral lactulose andat least one dose of parenteral vitamin K1. Doxycy-cline is the drug of choice for chlamydiosis. Metroni-dazole, cephalosporins and the penicillins are theantibacterials of choice for small mammal hepaticinfections. Investigations to determine the best anti-biotics for avian hepatitis have not been performed.

Pancreatic DiseasePrimary pancreatitis is seldom diagnosed in birds,but is occasionally found at necropsy.17a Bacterial,viral and chlamydial infections of other organs mayspread to the pancreas causing secondary problems.Acute pancreatic necrosis in an Umbrella Cockatoo38

and pancreatic atrophy in a Blue and Gold Macaw40

have been described. The underlying cause was notfound in these two birds; however, it was speculatedthat obesity and a high-fat diet contributed to diseasein the cockatoo.

Clinical signs of pancreatitis may include inappe-tence, lethargy, weight loss, polyuria, polydipsia, ab-

FIG 15.15 A mature Amazon parrot was presented with chronic diarrhea. On physicalexamination, an accumulation of excrement was noted in the pericloacal area and on thetail feathers. The cloacal mucosa was examined using a moistened cotton-tipped applica-tor. A tentative diagnosis of papillomatosis was made by identifying small, pink noduleson the cloacal mucosa (courtesy of Elizabeth Hillyer).


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dominal distension and abdominal pain. Pancreaticexocrine insufficiency results in polyphagia, weightloss and bulky, pale droppings (see Color 8).

A CBC and a biochemical profile that includes amy-lase and lipase levels are indicated. In cases of acutepancreatitis, a radiograph may demonstrate a hazyor fluid-filled abdomen. Initial treatment should in-clude aggressive parenteral fluid therapy and broad-spectrum antibiotics. One dose of rapidly acting cor-ticosteroid may be beneficial in some birds. Plantenzymes (rather than canine pancreatic enzymes)can be added to the tube-feeding formula to help withdigestion (see Chapter 18). Vitamin E and seleniumshould also be given, and the bird tested for zinctoxicosis.

Urogenital System

Egg BindingEgg binding is most common in hens that are on apoor diet, are first-time egg layers or are prolificlayers. Problems are most common and most severein smaller species such as cockatiels, budgerigarsand finches. Egg-laying is metabolically demanding,requiring large expenditures of protein, calcium andfat. Lack of sufficient dietary calcium, protein andtrace minerals such as vitamin E and selenium willpredispose to egg binding by resulting in soft-shelledeggs and uterine atony. Hypovitaminosis A is often acontributing factor due to alteration of mucosal in-tegrity.

Clinical signs of egg binding include lethargy, inap-petence, abdominal straining and remaining fluffedon the bottom of the enclosure. Owners often report“diarrhea.” Droppings often tend to be large and wetdue to cloacal relaxation associated with egg laying.In some birds there is a lack of droppings due to theegg’s interfering with normal defecation. The ownershould be questioned about previous egg laying activ-ity and for clues that would suggest nesting behavior(eg, paper-shredding, hiding under papers or in darkplaces and nest building).

On physical examination, the hen may appear weakand quiet. Tachypnea is common. Unilateral or, lesscommonly, bilateral leg lameness or paresis occurs ifthe egg is pressing on the ischiatic nerve as it runsthrough the pelvic region. In most cases an egg ispalpable in the abdomen. If the egg is poorly calcified,it may not be palpable but the abdominal region willbe moderately swollen and soft. The cloacal region isoften swollen also. Whole body radiographs can be

used to confirm the diagnosis. Medullary bone forma-tion, also termed hyperostosis or osteomyelos-clerosis, occurs under the influence of female repro-ductive hormones and is seen especially in the femur,tibiotarsus, radius and ulna (see Figure 12.65).

Occasionally, the presence of an egg with a non-calci-fied shell may be difficult to distinguish radiographi-cally from egg-related peritonitis or an abdominalmass. In this case, a repeat radiograph approxi-mately one hour after the administration of bariummay aid in localizing internal structures. An alterna-tive is to administer supportive care, calcium, vita-mins and antibiotics, and then to repeat the radio-graph one to two days later, assuming that an eggwould have calcified or passed in that time period.Uterine rupture is possible, and will negate this lastassumption (see Chapter 41).

Conservative medical treatment for egg binding isoften successful and should always be given a chanceto work before more aggressive therapy is instigated.Decisions regarding therapy should be based on thebird’s clinical condition, but in most cases, it is bestto allow up to 24 hours of medical therapy beforeinitiating more aggressive steps. Even with paresisof a leg, it is best to attempt medical therapy firstbecause the paresis usually resolves once the egg ispassed. Small birds such as finches may requireearlier intervention.19 The real emergency associatedwith a retained egg is that it may place excessivepressure on internal pelvic structures, such as thecaudal poles of the kidneys, where ischemic renalnecrosis may occur (Figure 15.16). In contrast, somebirds are not clinically ill from egg binding. An exam-ple is an egg-bound budgerigar that the authorstreated medically for six months because the ownersrefused surgery.

Medical therapy for egg binding includes fluids, lu-bricating the cloaca, supplemental heat and paren-teral calcium, vitamin A and vitamin D3. If the birdis anorectic, oral dextrose or a small gavage feedingmay be given, and the bird should be placed in awarm, moist environment such as an incubator con-taining wet towels. (An old-fashioned, sometimessuccessful, therapy for egg binding is to submerge thecaudal portion of the bird in a bowl of warm water forfive to ten minutes!) After one or two doses of cal-cium, an injection of oxytocin may promote egg pas-sage. Prostaglandin may be more effective in facili-tating the passage of an egg than oxytocin (seeChapter 29).


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If the egg has not passed in 24 hours, or if the birdappears to be weakening, two nonsurgical techniquescan be considered. The first works best if the egg islow in the abdomen. With the bird under isofluraneanesthesia to achieve full relaxation, the egg may bemanually pushed caudally so its tip is visible throughthe uterine opening into the cloaca (see Chapter 29).

An 18 to 22 ga needle is inserted intothe egg, the egg contents are with-drawn, the egg is carefully implodedand the egg shell fragments are with-drawn using a small hemostat (Fig-ure 15.17). Generally, the hen willpass any remaining egg shell frag-ments within several days.

The second technique is transab-dominal aspiration of egg contentsusing a large gauge needle (seeChapter 29). The egg is manipulatedto the ventral body wall and the eggcontents are removed with a syringe.The egg is then gently imploded, re-lieving pressure on pelvic structures.Supportive care and calcium are con-tinued until the bird delivers the eggshell on its own. Some cliniciansflush the uterus for several days to

prevent feces from contaminating the tramautizeduterus. The positive or negative effects of this proce-dure have not been studied. The disadvantage of thistechnique is that occasionally a hen does not pass theegg shell fragments, necessitating a hysterectomy.

Surgical removal of the egg via laparotomy is neces-sary if the uterus is ruptured, if an egg cannot passdue to adhesions or other causes, or if there aremultiple eggs (see Chapter 41).

Uterine ProlapseUterine prolapse containing an egg is common, par-ticularly in budgerigars. Occasionally the uterus willprolapse without the egg. Both conditions probablyresult from constant straining coupled with muscleweakness due to nutritional deficiencies or physicalexhaustion.

The bird is anesthetized with isoflurane to allowcareful examination of the prolapsed tissue. Whilethe bird is anesthetized, SC or IV fluids, parenteralcalcium, vitamins A and D3 and a broad-spectrumbacteriocidal antibiotic are administered. One dose ofa rapidly acting corticosteroid is appropriate if thebird appears to be in shock. The ureters, rectum andcloaca will sometimes prolapse with the uterus. Theprolapsed tissue should be flushed with sterile salineand replaced with a lubricated blunt probang, sterileswab or other sterile, blunt instrument (see Color29).

Oxytocin or prostaglandin (see Chapter 29) applieddirectly to the uterus will help reduce swelling and

FIG 15.16 An adult Amazon parrot was presented with an acute onset of lethargy andmild dyspnea. Abnormal clinical pathology changes included WBC=22,400, Ca=28.5 andLDH=750. A hard mass, suspected to be an egg, was palpable in the caudal abdomen.Radiographs indicated a calcified egg in the caudal abdomen and hyperostosis. The highCa level, elevated LDH activity and hyperostosis in the femur are all common with egglaying. This bird delivered a normal egg the day after evaluation.

FIG 15.17 A cockatiel hen was presented for depression, strainingto defecate and rear limb ataxia. A firm mass was palpable in thecaudal abdomen and an egg could be visualized through theurodeum using a small otoscope cone. The bird was given fivepercent dextrose SC, calcium and oxytocin IM and the cloaca waslubricated with a water-soluble jelly. The bird was placed in awarm incubator. One hour later, the bird was re-evaluated and hadnot improved. The egg was gently pinched into the cloaca, the eggcontents were removed with a needle and syringe, and the egg wascollapsed. The fragments of the egg were removed with hemostats.The bird was given SC fluids and corticosteroids and placed backin the incubator. The bird had returned to normal and was eatingwithin three hours (courtesy of Kathy Quesenberry).


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control bleeding. If an egg is in the prolapsed tissue,the open end of the prolapse should be identified andthe egg contents aspirated with a needle to gentlycollapse the egg. The egg is usually tightly adheredto the fine, transparent uterine tissue, which shouldbe liberally moistened with warm sterile saline. Amoist, sterile swab will help gently peel the uterinetissue from the egg without tearing. The prolapsedtissue should be flushed again and replaced as de-scribed. The need for a retention suture in the cloacais based on clinical judgment.

The prognosis for recovery depends on the extent oftissue trauma. In the authors’ experience, many hensrespond well to therapy even if the replaced uterinetissue appears severely desiccated or inflamed. Anti-biotic therapy for five to seven days is recommended.Any remaining necrotic areas should be exteriorizedand amputated. The necrotic areas are sutured with4-0 or 5-0 absorbable suture material, being carefulto avoid the ureters.19 Most birds will temporarilycease egg laying after the trauma and illness associ-ated with uterine prolapse. After the bird is stable, ahysterectomy may be necessary to prevent futureegg-related problems.

Egg-related PeritonitisEgg-related peritonitis is thought to occur because ofa failure of the ovum to enter the infundibulum. Theperitonitis that occurs is usually sterile, but may becomplicated by secondary bacterial infection. Thecondition is seen most commonly in cockatiels, love-birds and budgerigars, but can occur in any hen.

The history usually includes a gradual onset of leth-argy, weakness, inappetence, tachypnea and dysp-nea. Nesting or egg-laying behavior often precedesthe onset of illness. Occasionally, a bird will show noclinical signs other than tachypnea or dyspnea re-lated to fluid accumulation in the abdomen. Theclinical presentation of egg-related peritonitis varieswith the species. Ascites is most common in cocka-tiels.

On physical examination, the bird is found to have afluid-filled, distended abdomen. If the bird is dysp-neic, it should be placed in an oxygen-rich environ-ment prior to diagnostics and treatment. Abdomino-centesis is performed with a 23 or 25 ga butterflycatheter or an appropriately sized needle and syringe(see Chapter 10). Only a sufficient volume of fluid torelieve the dyspnea should be removed. The needle ispassed into the abdomen just below the end of thekeel. Care should be exercised to prevent laceration

of the liver if hepatomegaly is suspected. Fluid drain-age can be attempted from several sites, choosingavascular areas of skin. Fluid may range from yellowto rust-colored and may be clear or cloudy. More thanone abdominocentesis may be necessary. Some vet-erinarians prefer to place a Penrose drain to allow acontinuous port for fluid removal.19

Fluid analysis and cytology, a CBC and whole bodyradiographs should be performed. Radiographicchanges are characterized by a fluid-filled abdomenwith loss of detail. Increased ossification in the longbones suggests that calcium is being stored for im-pending ovulation. Parenteral fluids, a broad-spec-trum antibiotic and an anti-inflammatory dose ofcorticosteroid should be administered. Although cor-ticosteroids should be used with caution in birds,low-dose corticosteroid therapy for two to five days inconjunction with antibiotics appears to be beneficialin birds with egg-related peritonitis. A course of me-droxyprogesterone acetate is a common companiontherapy to steroids (see Chapter 29). A laparotomyand abdominal lavage may be necessary in birds withsevere or non-responsive egg-related peritonitis (seeChapter 41).

Renal FailureRenal failure is uncommonly diagnosed in avianmedicine (see Chapter 21). Possible causes includesome toxicities, ureteral obstruction and trauma(such as occurs with egg binding) and bacterial, viral,fungal or parasitic infections.

Clinical signs include polyuria, polydipsia, inappe-tence, depression and dehydration. Uric acid depositsmay be visible on joint surfaces. The basic databaseconsists of a CBC, biochemistry analysis, urinalysis,fecal Gram’s stain and fecal culture.52 Radiographsare useful to evaluate the size and density of therenal shadows. Uric acid deposits are radiolucent butrenal mineralization will be visible on radiographs.

Emergency treatment consists of subcutaneous orintravenous fluids, antibiotics and a multi vitamininjection. The latter would be contraindicated if hy-pervitaminosis is suspected (eg, vitamin D toxicosisin macaws).

Respiratory System

DyspneaDyspnea in birds is characterized by open-mouthedbreathing, prominent abdominal excursions and tail-bobbing with respiration. Causes of dyspnea can be


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divided into two categories: primary respiratory andextra-respiratory disease. Primary respiratory dis-ease occurs in the trachea, lungs or air sacs and maybe caused by viral, bacterial, fungal, parasitic,chlamydial and mycoplasmal infections, inhaled tox-ins or foreign body aspiration. Extra-respiratory dis-eases can cause dyspnea by interfering with normalair flow patterns through the respiratory tree or bylimiting expansion of the lungs and air sacs. Thiscategory includes thyroid enlargement, abdominalmasses, abdominal fluid and oral masses such aspapillomas. Birds with severe rhinitis, impactednares, choanal atresia or sinusitis may also showopen-mouth breathing and a tail-bob because theycannot breathe through the nares. Anemia may alsoinduce dyspnea (see Chapter 22).

A thorough history should include questions regard-ing the possibility of exposure to other birds or toair-borne toxins, the possibility of foreign body aspir-ation and recent evidence of crop stasis or ileus,which may lead to aspiration. Before a dyspneic birdis handled, it should be carefully observed for con-junctivitis, swollen sinuses, nasal discharge and res-piratory sounds. Budgerigars with goiter may have ahigh-pitched voice or a squeak with each respiration.These birds are also prone to crop-emptying prob-lems and may have a dilated crop. Birds with infec-tious respiratory conditions often have conjunctivi-tis, swollen sinuses or nasal discharge. Mynah birdsand toucans may develop cardiomyopathy or iron-storage hepatopathy, resulting in ascites and dysp-nea. Egg binding or egg-related peritonitis should beconsidered as a cause of dyspnea if the bird has ahistory of egg laying. The bird should be placed in anoxygen-rich environment while diagnostic and treat-ment plans are being formulated.

Some birds may benefit from immediate placementof an air sac tube (see Figure 15.10) while diagnostictests are performed. If a bacterial pneumonia or airsacculitis is likely, antibiotics may be administeredby nebulization in order to minimize handling. Alter-natively, the bird may be anesthetized with isoflu-rane to collect diagnostic samples and initiate ther-apy. Initial diagnostic tests should includeradiographs, CBC, biochemistry profile, abdominalfluid analysis (if present) and tracheal wash. Birdswith ascites or egg-related peritonitis will often im-prove once the abdominal fluid is removed. Early inthe course of therapy, enough fluid should be with-drawn to relieve dyspnea and provide a diagnosticsample. In theory, sudden withdrawal of too muchfluid can cause hypovolemia and shock;11,19 however,

in practice, the authors have not experienced thisproblem. A 23 to 25 ga butterfly catheter or fine-gauge needle and syringe are used to aspirate fromseveral sites through areas of avascular skin.

A tracheal wash should be performed just before thebird recovers from anesthesia. A sterile catheter ortube is passed into the tracheal opening. With thebird held parallel to the floor, sterile saline (up to10ml/kg) is infused into the trachea and immediatelyaspirated. Cytology and bacterial and fungal culturecan be used to evaluate the aspirated material.

General supportive care, including fluid therapy,heat, vitamins and nutritional support, is adminis-tered according to the patient’s ability to withstandhandling. Specific therapy is given according to thedifferential diagnosis (see Chapter 22).

Acute DyspneaAcute onset of dyspnea in a previously healthy birdis usually due to one of three causes: 1) inhalation ofa toxin, 2) plugging of the trachea by dislocation of aninfectious plaque from the choana or tracheal bifur-cation or 3) inhalation of a foreign body such as seedor bedding material. Inhalation of small seeds bycockatiels is common.

When a blockage of the upper respiratory tract issuspected, an air sac tube will provide immediaterelief of dyspnea. The bird can be anesthetized byadministering isoflurane through the air sac tube,making it possible to examine the trachea endoscopi-cally. In smaller birds, transillumination of the tra-chea may be used to identify tracheal foreign bodies.Radiographs often demonstrate the site of obstruc-tion and will also allow for evaluation of the lungsand air sacs. Removal of a tracheal foreign body isaccomplished using suction or a biopsy forceps. Insome cases it may be necessary to perform a trache-otomy by incising between tracheal rings just distalto the foreign material. The foreign body is retrievedwith biopsy forceps or pushed up and out of thetrachea using a blunt probang.19

Air Sac RuptureRupture of an air sac often results in a balloon-likedeformity of the skin (see Figure 22.12). While theclinical appearance is quite alarming to owners, theproblem is rarely a true emergency. Rupture of acervicocephalic air sac in small birds is most com-mon. The rupture is usually acute, but gradual onsetis seen also. Most birds are reported to be otherwisenormal and the cause of the rupture is not identified.


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On physical examination, a soft, air-filled swelling ispalpable. The swelling will involve the head and neckregion when the cervicocephalic air sacs are involved.A small needle and syringe can be used to aspiratesome air and confirm the diagnosis. A medicalworkup should be considered if the bird is showingclinical signs of illness, particularly those associatedwith respiratory disease.

Initial treatment for air sac rupture involves makinga percutaneous fistula to allow for continued drain-age of air. This relieves pressure on the site of rup-ture to allow for healing. A rapid, simple technique isto use a hand-held ophthalmic cauteryo to make a oneto two centimeter opening in an avascular area ofskin over the swelling, causing rapid deflation. Occa-sionally the swelling may recur when the fistulacloses and the technique must be repeated, making alarger fistula. Surgical repair may be necessary insome birds if initial treatment fails (see Chapter 41).

Neurologic System

Head TraumaCompanion birds are often presented with headtrauma caused from flying into ceiling fans, mirrors,windows and walls. Free-ranging birds may be in-jured by colliding with buildings, windows or auto-mobiles.

Birds frequently recover from seemingly severe headtrauma. Examination should include visual asses-ment for alertness and neurologic signs, an evalu-ation for shock, and examination of the cranium,eyes, nares and ears for evidence of fractures, hemor-rhage or bruising. If the trauma is recent, treatmentconsists of IV or IM rapidly acting corticosteroid andplacement of the bird in a dark environment main-tained at a comfortable (cool) temperature. A warmenvironment may potentiate intracranial vasodila-tion. If the bird is in shock, IV fluids are given atone-half to two-thirds of the normal volume to avoidoverhydration and cerebral edema. The use of diuret-ics is controversial in mammals with head trauma,59

but mannitol or furosemide may be beneficial if thebird does not respond to initial therapy. Short-termmonitoring consists of neurologic evaluation andmeasurement of blood glucose.

Birds may be presented with severe neurologic ab-normalities from head trauma that occurred severaldays earlier. If the trauma occurred over 24 hourspreviously, an empirical course of antibiotics andshort-term corticosteroids can be attempted, but this

is usually ineffective. Neurologic impairment may bepermanent if the injury is several days old and noimprovement is noted following 48 hours of therapy.Long-term corticosteroid therapy should be avoidedin such birds.24

SeizuresAlthough the study of avian neurology is in its in-fancy, most seizure disorders in birds can be managedeffectively, even if the exact cause is not determined.Avian seizures have not been classified according tothe criteria used in mammals; however, several dif-ferent types of seizure activity are seen clinically.Mild seizures are characterized by a short period ofdisorientation with ataxia and inability to perch.Generalized seizures are characterized by a loss ofconsciousness, vocalizing, wing flapping and pad-dling. Partial seizures are characterized by persist-ent twitching or motor activity of the head or one ofthe extremities. They can be continuous and chronic,and frequently go unrecognized by the owner becausethey are less dramatic than generalized seizures.

Causes of seizures in birds include primary centralnervous system (CNS) disease resulting fromtrauma, hyperthermia, vascular accidents, infectionor neoplasia, and metabolic problems such as hypo-calcemia, hypoglycemia, hepatoencephalopathy,toxin exposure and fat emboli. Idiopathic epilepsy, adiagnosis of exclusion, has been reported in Peach-faced Lovebirds, Red-lored Amazon Parrots, DoubleYellow-headed Amazon Parrots and mynahbirds.53,55,56,68 A syndrome of hypocalcemia causingweakness and seizures occurs in African Grey Par-rots.55 Cockatiels and lovebirds may show neurologicsigns with an undiagnosed, fear-induced mild flap-ping of the wings, or occasionally with chlamydiosis.Egg-laying birds often have severe lipemia and maydevelop fat emboli with resultant neurologic abnor-malities including seizures and paralysis. Hypogly-cemic seizures occur most commonly in raptors andneonates of other species.

The history should include questions regarding diet,egg laying and possible toxin exposure. Ownersrarely can verify heavy metal exposure although it iscommon in psittacine birds due to their propensityfor chewing on toys and household objects. Even toysmanufactured expressly for birds should not be as-sumed to be safe.67 If the bird is not actively seizur-ing, a full physical and neurologic examination in-cluding a CBC, biochemical analysis and blood metalconcentration should constitute the minimum data-base in most cases (see Chapter 37). Radiographs are


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useful to evaluate bone quality and screen for metal-lic particles in the gastrointestinal tract. If the birdis weak or actively seizuring, an in-house blood glu-cose test should be performed. Abnormal values areless than 50% of the published normal referenceinterval for the species (see Appendix).44

While laboratory results are pending, treatment forbirds not actively seizuring consists of general sup-portive care. If the bird is seizuring on presentation,the first goal of therapy is to stop the seizure activitywith IM or IV diazepam. Intravenous phenobarbitalshould be underdosed and used with caution inbirds.19 If lead or zinc poisoning is a possibility, treat-ment with CaEDTA should begin immediately. Hy-perthermia should be evaluated and treated, andhypoglycemia should be corrected with IV dextrose.Suspected chlamydiosis or other infectious diseasesshould be treated accordingly.

Seizure activity associated with hypocalcemia ismost common in African Grey Parrots and youngbirds on a poor diet. The African Grey hypocalcemicsyndrome is thought to occur because of a lack ofcompensatory mechanisms to maintain serum cal-cium levels.55 The syndrome may actually representa deficiency of vitamin D3; however marginal dietarycalcium levels seem to play a role.68 These birds canhave a serum calcium concentration as low as 2.5mg/ml. Radiographically, the skeletal mineralizationappears normal, indicating an inability to mobilizeskeletal calcium. Other species that develop hypocal-cemia will show decreased bone density, folding frac-tures and pathologic fractures. Treatment for hypo-calcemia consists of parenteral calcium, vitamin D3

and supportive care.

ComaComa can result from head trauma, toxin ingestion,hyperthermia, CNS infection or neoplasia, cerebralischemia due to a vascular accident, or severe meta-bolic disease such as hepatic encephalopathy or uricacidemia. The history should include questions re-lated to the onset of clinical signs and possibletrauma, toxin ingestion or inhalation (carbon monox-ide) and exposure to viruses or parasites (eg, Sarco-cystis spp. , Baylisascaris sp.).

Ensuring a patient’s airway and adequate ventila-tion are of primary importance. Establishing an air-way with a tracheal or air sac tube and placing thebird in an oxygen-rich environment or applying posi-tive-pressure ventilation may be necessary. The birdshould be given dextrose IV if an in-house test indi-

cates hypoglycemia. Emergency treatment consistsof IV fluids (low dose if cerebral edema is a possibil-ity), parenteral corticosteroids and treatment for hy-perthermia as necessary. The use of IV diuretics suchas mannitol or furosemide should be considered inbirds with head trauma and hyperthermia. Bacter-iocidal antibiotics or doxycycline for chlamydiosismay be indicated in some patients. The bird shouldbe placed in a dark, cool enviroment after treatmentto discourage cerebral vasodilation and edema.

The prognosis for recovery depends on the patient’sprogress during the first two days of therapy. Suppor-tive care should include lubrication of the eyes andfrequent turning of the recumbent bird as necessary.

Paralysis of Acute OnsetParesis or paralysis of one or both legs is seen morecommonly than problems with the wings. Possiblecauses of leg paresis include soft tissue trauma, frac-tures, osteoporosis, neural infections or vertebraltrauma or neoplasia. Fractured leg bones are usuallyassociated with reversible paresis of the foot andtoes. Another cause of unilateral or, less commonly,bilateral leg paresis is pressure on the pelvic portionof the ischiatic nerve caused by egg binding or renalor gonadal tumors (see Color 25). Paresis of a wing isindicated by a wing droop. This is most commonlycaused by soft tissue or bony trauma. Occasionallylead or other heavy metal toxicity will cause periph-eral neuropathy resulting in wing or leg paresis.

A neurologic examination of affected birds shouldinclude assessment of cloacal tone, grasping strengthof the feet and ability to move the tail (see Chapter28). Muscles may undergo atrophy in the affectedlimb. The feathers should be parted with alcohol inorder to examine the skin for evidence of bruising orwounds. This technique is useful for detection offractures. The skin overlying the skull and spineshould also be examined.

In many cases, the cause of the paresis or paralysisis evident on physical examination but radiographsmay be useful to detect or assess intra-abdominalmasses, metallic densities in the GI tract, coxofemo-ral luxations, or fractures of the spine, long bones orshoulder girdle. If heavy metal poisoning is a possi-bility, blood levels of lead or zinc can be determined.

Treatment is tailored to the specific condition. Eggbinding and fractures are managed routinely. Paretictoes must be taped in the proper perching position toavoid knuckling and resultant damage to the top ofthe foot. One to three days of corticosteroid therapy


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may be indicated in cases of head or vertebraltrauma. In general, birds have a good capacity forreturn to function after the cause of the paresis orparalysis is resolved. An Amazon parrot with a pelvicplexus avulsion, incurred when its foot was trappedbetween the cage bars, had no perceptible sensationor function of the leg or foot. Treatment consisted ofone dose of rapidly acting corticosteroid and sevendays of a broad-spectrum antibiotic. A gradual returnof sensation began around one month and the birdwas back to normal at three months. It is impossibleto predict the possibility of recovery with most avianneurologic injuries.

Chronic Disease With Acute PresentationBirds are able to hide subtle signs of disease fromowners until illness is advanced. The most commonavian emergency presented to avian clinicians is achronically ill bird that has decompensated to thepoint where the owner finally becomes aware of theillness. These birds are usually debilitated, dehy-drated and cachectic. It is important with these pa-tients to minimize stress (eg, loud noises, brightlights and excess handling). These birds generallyrequire therapy for severe dehydration and cachexia.Emaciated birds are frequently anemic. Some birdsbegin to eat on their own within a short time after theinitiation of therapy. Birds that refuse to eat shouldreceive an easily digestible enteral preparation suchas Isocal-HCN.k

Occasionally a cachectic bird will be presented that isalert and relatively active with a good appetite. Theowner may not be aware of the weight loss and mayhave brought the bird in for another problem. This isa common presentation in birds with tuberculosisand some neoplasias. Although the bird may appearstrong, its body fat and glycogen stores are depletedand it may decompensate as easily as birds thatappear weaker. Prognosis for cachectic birds is grave.

Physical Injury

Animal BitesBirds that have been attacked by a mammal or an-other bird are often presented for emergency evalu-ation. Bite-induced injuries are typically of the crush-ing and tearing type, often necessitating surgicalrepair or debridement of damaged tissue (see Chap-ter 16). Mammal bites are usually from a pet dog orcat. These are true emergencies and require immedi-ate attention due to the pathogenic oral bacteria thatare introduced deep into bite wounds. Cat attacks, inparticular, are especially dangerous because many

cats carry Pasteurella multocida on the gingival tis-sue and teeth.

Shock therapy is instituted if necessary. For a carni-vore bite, treatment with a bacteriocidal antibioticshould begin immediately. Penicillins are the antibi-otics of choice for cat bites because of their efficacyagainst P. multocida. All wounds must be flushedwith copious volumes of warm sterile saline or 0.05%chlorhexidine. If they are difficult to find, smallamounts of alcohol may be used to part the feathers,keeping in mind that there are usually two wounds,one from either jaw, associated with a bite. Puncturewounds must be left open for drainage, but largegaping lacerations may require partial closure.

BurnsThe most common burns in birds occur on the legsand feet. These result when free-flighted birds landin hot cooking oil, hot water or on a hot surface.Burns to the oral mucosa and tongue may occur whenbirds bite on electric cords (see Color 24).

The treatment for burns involves basic supportivecare, topical therapy and prevention of secondaryinfection while the wounds are healing. Secondaryinvaders are typically Staphylococcus intermedius,streptococci, coliforms and Pseudomonas spp. Sys-temic antibiotics and corticosteroids should beavoided during initial therapy because their use maypredispose the patient to immunosuppression andnosocomial infection.57

Diligent topical therapy is the key to burn manage-ment. The burned areas should be flushed with copi-ous amounts of cool water or saline. Feathers sur-rounding the wounds should be removed to allow foraeration. Water-soluble, topical antibacterial creamssuch as silver sulfadiazinex should be used instead ofgreasy or oily medications. If the wound is not in-fected (Gram’s stain of cleansed wound negative fororganisms), a hydroactive dressingp is beneficial toprevent water loss and promote granulation tissue(see Chapter 16). Wounds should be flushed twicedaily and debrided once a day.

Gram’s staining and culture and sensitivity ofburned tissue may be indicated to monitor for infec-tion. Systemic antibiotic therapy is initiated based onpositive culture results. In humans, early surgicalclosure of burn wounds is beneficial. Perioperativeantibiotic therapy may prevent surgically inducedbacteremia or endotoxemia.57


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Glue TrapsFree-flighted companion birds can become caught inglue traps intended for rodents. Trapped birds usu-ally struggle, entangling many contour and primaryfeathers in the glue. Unless the bird can be removedfrom the trap with relative ease, the client should beinstructed to bring the bird to the hospital still at-tached to the glue device.

Removing a bird from the glue entails gentle re-straint of the body while freeing one extremity at atime. Feathers may be cut or gently removed. Shocktherapy and supportive care should be given asneeded. To prevent ingestion, the glue remaining onthe bird must be removed before preening activity isallowed. Ether, acetone and water are ineffective. Acommercial automobile protectantq is nontoxic andcan be rubbed gently on affected feathers to removethe glue. This material can be rinsed away with warmwater. These agents should be used with caution be-cause some products contain lead (see Chapter 37).

Exposure

OilThe avian veterinarian may be called on to treat free-ranging birds caught in an oil spill, companion birdsthat have flown into household oils, or birds whoseowners have applied greasy, over-the-counter medica-tions as topical mite or wound therapies (see Color 24).Large quantities of oil on the feathers disrupt normalthermoregulatory mechanisms and may result in hy-pothermia and coma (Figure 15.18). Oil-contaminatedbirds may also suffer from blockage of the nares andconjunctivitis. Systemic toxicity and GI upset may oc-cur if the oil is ingested during preening.

The goals of treating oil-soaked birds are to reverseshock, prevent or treat hypothermia, provide basicsupportive care and remove the oil from the feathers,nares and oral cavity. The bird is wrapped in a towelor thermal blanket to conserve body heat, and shocktherapy is initiated if needed. The eyes are lubricatedand oil is removed from the nares and oral cavitywith a swab. Depending on the bird’s tolerance forrestraint, it may be necessary to alternate rest peri-ods in a dark, heated environment (95°F) with warmbaths (100 to 105°F) to remove the oil. A commercialdish-washing detergentr is a safe and effective sol-vent and is used in decreasing concentrations insequential baths with thorough warm water rinses inbetween.71 When the feathers are clean, the bird isdried with a blow-dryer and placed in a warm envi-ronment.

HyperthermiaPanting and holding the wings away from the bodyindicate hyperthermia in birds. Birds do not havesweat glands and do not dissipate heat efficiently. Ifallowed to progress, hyperthermia results in ataxia,seizures and coma.

The first goal of emergency therapy is to reduce bodytemperature by placing the feet and legs in cool waterand wetting the feathers down to the skin with wateror alcohol. If the bird is severely overheated, coolwater can be infused into the cloaca, taking care notto induce hypothermia by overzealous cooling.Flunixin meglumine may be used to reduce hyper-thermia rapidly and safely. A bird in shock should begiven low doses of IV or SC fluids, and one dose ofrapidly acting corticosteroid. Mannitol or furosemidemay help control cerebral edema.

FrostbiteFrostbite injuries in birds generally occur on the feetand toes, but may also occur around large metalidentification bands that are exposed to freezing tem-peratures. If the injury is recent, the frozen tissuesappear pale, dry and avascular, sometimes with aswollen area proximally. If left untreated, the frozentissue will become necrotic with an erythematousline of demarcation separating it from viable tissue.Ascending infections and gangrene do not appear tobe complications of frostbite in birds.

Treatment of a recent frostbite injury involves grad-ual warming of the extremity by placing the affectedtissue in circulating water baths and increasing thewater temperature over a 20- to 30-minute period. If

FIG 15.18 The most life-threatening concern with an oil-contami-nated bird is hypothermia. Oil should be removed from the nostrilsand oral cavity with cotton-tipped applicators and from the feath-ers with repeated baths in warm dish-washing detergent (courtesyof J Assoc Avian Vet).


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the tissue becomes necrotic, it can be surgically am-putated at a later date (see Chapter 41).

General Emergency Principles of Toxin ExposureToxicity problems in companion birds are extremelycommon, with heavy metal poisoning leading thelist.24 Toxins that may enter by the alimentary routeinclude lead, zinc and other heavy metals, variousplants, rodenticides and some foods like chocolate(see Chapter 37). Birds are also very sensitive toaerosolized toxins, which include overheatedpolytetrafluroethylene (Teflon or other non-stick coat-ings), tobacco smoke, hair spray, pesticides, paintfumes, naphthalene, ammonia and carbon monoxide.Leaded fumes or dust can cause lead toxicity by inha-lation in mammals. Iatrogenic drug toxicities may oc-cur due to species or individual differences in drugmetabolism or errors in administration or dosing.

Ingestion of prey animals or contaminated watermay expose free-ranging birds to potential toxins, themost common being organophosphates, botulismtoxin and lead.39

Clinical signs of toxicity vary widely and may includedepression, anorexia, diarrhea, regurgitation, dysp-nea and neurologic signs including ataxia, seizures,head tilt and peripheral neuropathy. Amazon parrotsmay have hemoglobinuria with acute lead toxicity.Occasionally a bird will be exposed deliberately orallowed unrestricted access to substances such aschocolate, alcohol or marijuana. Careful and specificquestioning is usually necessary to delineate poten-tial toxin exposure.

The first step in treatment of any toxin exposure is tostabilize the patient as necessary with shock andanticonvulsant therapy. If a known toxin was re-cently ingested, a crop lavage is the quickest methodof removal. An ingluvotomy may be necessary toremove solid toxins (see Chapter 41). If more thanone-half hour has passed since ingestion, a poisoncontrol center should be contacted (see Chapter 37).

Most often, an exposure to a specific toxin cannot beidentified. A CBC and biochemistry analysis, bloodlead and zinc concentration and radiographs are in-dicated. Nonspecific treatment for suspected toxico-sis includes decreasing further absorption of thetoxin from the GI tract, hastening elimination of thetoxin and providing supportive care. If heavy metaltoxicity is a possibility, treatment with Ca EDTAshould be initiated.

QUICK REFERENCE FOR EMERGENCY TREATMENT

ANIMAL BITESParenteral penicillin ASAPClean wounds

BLOOD LOSS/ANEMIAStop bleedingVolume replacement (IV or IO fluids)Iron dextranB vitaminsVitamin K1Blood transfusion (PCV <20%)

BURNSGently remove feathersClean wounds Antimicrobial creamsHydroactive dressing if not infected

CACHEXIAFluids - IV or IO5% dextrose IV or IOOral or parenteral alimentation

COMAEnsure patent airwayOxygen-rich environmentLow dose fluids if dehydratedSingle-dose corticosteroidsMannitol or furosemide

CPREstablish airway - air sac tubeVentilate every 4 to 5 secsRapidly press on cranial sternumEpinephrine and doxapram IC, IO, IT

DIARRHEAFluids (IV, IO)Bactericidal antibioticsShock therapy if necessary

DYSPNEAURD - air sac tubeOxygen-rich enclosureRemoval of some ascitic fluidRemove tracheal foreign bodies (suction or surgery)

EGG BINDINGMedical therapy initially:Subcutaneous fluidsLubricate cloacaProstaglandinParenteral calcium and oxytocinDextrose oral (50%) SC (5%) Vitamins A and D3Supplemental heat

If medical therapy fails:Assisted cloacal deliveryPercutaneous ovocentesisVentral laparotomy

FROSTBITEGradual warming in water bathIncrease temperature

HEAD TRAUMACorticosteroids - IV, IODark, cool environmentMinimal fluids - correct shock only

HYPERTHERMIAWet with cool waterFlunixin meglumineMannitolSingle dose corticosteroidsDry and keep at 85°F

LIVER DISEASEFluids (IV, IO)LactuloseVitamin K1Doxycycline - if suspect chlamydiaParenteral penicillin - if suspect bacteria

OILShock therapyPrevent hypothermiaBathing in warm detergent

PANCREATITISFluids (IO)Bactericidal antibioticsSingle-dose corticosteroidsNPO if possible

PROLAPSED CLOACAKeep tissues moist and cleanReplace cleansed tissueCorrect underlying urogenital or GI problemRetention suture if necessary

PROLAPSED UTERUSClean with sterile salineTopical oxytocin or prostaglandin to reduce swellingLubricate with water-soluble gelReplace with blunt probangRetention suture if necessary

REGURGITATIONFluids (IV, IO)Remove foreign bodies or toxinsGastric lavageSpecific toxin antidotesAppropriate antimicrobials

SEIZURESDiazepam - IV or IMSupportive careAfrican Grey Parrots - calcium and vitamin D3Raptors and neonates - glucose if needed

SHOCKFluids (IV or IO)Corticosteroids (IV or IO)Bicarbonate if acidoticBactericidal antibiotics if septic

SUPPORTIVE CAREFluidsHeatVitamin/mineral supplementsNutritional support

TOXINSTreat for shockRemove ingested foreign bodiesOxygen for inhaled toxinsSpecific antidotes (see Chapter 37)


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If the ingested toxin is still in the GI tract, lavage isperformed with saline or activated charcoal. Crop,proventricular and ventricular lavage are best per-formed with the bird intubated and under isofluraneanesthesia. A tube is passed into the proventriculusper os or a small crop incision is made and a redrubber tube is passed distally. The bird can be heldwith the head tilted down, and foreign objects andtoxins can be retrieved by flushing.67 The administra-tion of activated charcoal helps to bind toxins anddecrease GI absorption.

Saline and osmotic cathartics are used to speedelimination of toxins. Saline cathartics (eg, sodiumsulfate [Glauber’s salt])will precipitate heavy metalin the GI tract, decreasing absorption. Psyllium is anosmotic cathartic.29 For specific toxin therapies seeChapter 37.

Products Mentioned in Texta. Metamucil, Proctor and Gamble, Cincinnati, OHb. Nexaband, Tri-point Medical, Raleigh, NCc. Buretrol Add-On Set, Baxter Healthcare Corp, Deerfield, ILd. Baxter Healthcare Corp, Deerfield, ILe. Vibramycin Hyclate Intravenous, Roerig Division, Pfizer, Inc,

New York, NYf. Vibravenös, Pfizer, Inc, Zurich; London, Ontariog. Boehringer Mannheim Corp, Indianapolis, INh. PEP-E, Phylomed, Plantation, FLi. Animosyn II, Abbott laboratories, North Chicago, ILj. Liposyn II, Abbott Laboratories, North Chicago, ILk. Mead Johnson Nutritionals, Evansville, INl. Ross Laboratories, Columbus, OHm. OXA-10 oxygen analyzer, Avtech Systems, San Diego, CAn. Reglan, AH Robins, Cherry Hill, NJo. Storz Sure-Temp Surgical Cautery, Storz Instrument Co.,

St. Louis, MOp. DuoDerm hydro-active dressing, Convatec, Squibb, Canadaq. Armor All Protectant, Armor All Products Corp., Irvine, CAr. Dawn dish detergent, Proctor and Gamble, Cincinnati, OHs. Lipomul, The Upjohn Company, Kalamazoo, MIt. Leadcheck Swabs, Hybrivet Systems, Framingham, MAu. Injacom-100, La Roche, Nutley, NJv. Spinal needles, Baxter, Valencia, CAw. Gatorade, Gatorade Co., Chicago, ILx. Silvadene, Marion Labs Inc., Kansas City, MO

TABLE 15.6 Suggested Equipment for Avian Emergency Practice (items not commonly found in a standard small animal practice)

Incubator with temperature control, temperature and humidity sen-sors, oxygen port

Nebulizer (ultrasonic)

Anesthesia machine with isoflurane

Bipolar radiosurgical unit

Hand-held ophthalmic cautery devices

5-0 and 6-0 absorbable and nonabsorbable suture material

Endotracheal tubes (2.0 and larger)

Pre-sterilized air sac tubes of different sizes (shortened endotra-cheal tubes, red rubber tubes, others)

18 to 22 ga spinal needles (for use as intraosseous cannulas)

24 ga short, indwelling catheters

25 ga butterfly catheters with 3.5 inch tubing

Buretrol or Control-a-Flow extension sets

Low-dose insulin syringes (for accurate measuring down to 0.01 cc)

Leg band cutters

Metal feeding needles

Various sizes of red rubber tubes (for crop and GI lavage)

Catheter-tipped syringes

Catheter-tip adapters

Enteral feeding formula

Seeds, spray millet, other foods for inpatients

References and Suggested Reading

1.Abou-Madi N, Kollias GV: Avian fluidtherapy. In Kirk RW, Bonagura JD(eds): Current Veterinary TherapyXI. Philadelphia, WB Saunders Co,1992, pp 1154-1159.

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4.Birrenkott GP, Wiggins ME: Determi-nation of dexamethasone and corticos-terone half-lives in male broilers.Poult Sci 63:1064-1068, 1984.

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6.Bos JH, et al: Treatment of anemicbirds with iron dextran therapy: Ho-mologous and heterologous blood

transfusions. Proc Assoc Avian Vet,1990, pp 221-225.

7.Bracken JM, et al: A randomized con-trolled trial of methylprednisolone ornaloxone in the treatment of acutespinal cord injury. New Engl J Med58:1405-1411, 1990.

8.Brown SA, Hall ED: Role of oxygen-de-rived free radicals in the pathogene-sis of shock and trauma, with focuson central nervous system injuries. JAm Vet Med Assoc 200(12):1849-1858, 1992.

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10.Coles BH: Cloacal prolapse: A recur-rent emergency for the practitioner.Proc Euro Assoc Avian Vet, 1991, pp323-331.

11.Campbell TW: Cytology of abdominaleffusions. In Avian Hematology andCytology. Ames, Iowa State Univer-sity Press, 1988, pp 41-44.

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enrofloxacin. Proc Assoc Avian Vet,1989, pp 1-2.

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