Venipuncture and Venipuncture and Clinical Pathology for Clinical Pathology for

ReptilesReptiles

IntroductionIntroduction

► ReptilesReptiles stoicstoic evolved to mask evolved to mask

illnessillness

► Treat n’ run?Treat n’ run?►Diagnostic TestsDiagnostic Tests

to identify to identify physiologic physiologic anomaliesanomalies

Weight the reptile first Weight the reptile first

Blood CollectionBlood Collection

►Blood volume:Blood volume: 5-8% of body weight reptiles5-8% of body weight reptiles

►Tolerate 1% lossTolerate 1% loss

►General rule of thumb: General rule of thumb: 0.5-0.8 ml/100 g (reptiles)0.5-0.8 ml/100 g (reptiles)

►To heparinize or not to heparinize?To heparinize or not to heparinize? Consider time to collectConsider time to collect LIMIT VOLUME OF HEPARINLIMIT VOLUME OF HEPARIN May affect cell stainingMay affect cell staining

Venipuncture sites: LizardsVenipuncture sites: Lizards

► Ventral coccygeal/tail Ventral coccygeal/tail veinvein

► Ventral abdominal veinVentral abdominal vein

► JugularJugular

► Cardiac- euthanasiaCardiac- euthanasia

► Toe nailToe nail

Venipuncture sites: SnakesVenipuncture sites: Snakes

► CardiacCardiac

► Ventral tail veinVentral tail vein

Venipuncture sites: Venipuncture sites: CheloniansChelonians

► JugularJugular

►Dorsal coccygealDorsal coccygeal

► BrachialBrachial

► SubcarapacialSubcarapacial

SubcarapacialSubcarapacial

Venipuncture sites: Venipuncture sites: CrocodiliansCrocodilians

► Ventral tailVentral tail

► Ventral abdominalVentral abdominal

► CardiacCardiac

► SupravertebralSupravertebral

Blood collection tubes: Blood collection tubes:

Ethylene diamine tetra acetic acidEthylene diamine tetra acetic acid ►CBC and plasma CBC and plasma

chemistrychemistry►use microtainersuse microtainers

less likely to dilute less likely to dilute samplesample

do not overfill- do not overfill- microclotsmicroclots

►disadvantages:disadvantages: hemolyzes RBC’s: hemolyzes RBC’s:

especially tortoisesespecially tortoises elevated elevated

potassium*potassium* decreased calcium*decreased calcium*

Blood collection tubes: Blood collection tubes: Lithium heparinLithium heparin

► CBC or plasma CBC or plasma chemistrieschemistries less damaging to less damaging to

cellscells centrifuge centrifuge

immediately immediately ►cells will consume cells will consume

glucoseglucose►potassium and potassium and

phosphorus increase phosphorus increase from leakagefrom leakage

Blood collection tubes: Blood collection tubes: No anticoagulantNo anticoagulant

►Red top tubeRed top tube centrifuge to collect centrifuge to collect

serumserum serum may form serum may form

gelatinous clotgelatinous clot►may lose samplemay lose sample►continue to centrifuge, continue to centrifuge,

may helpmay help►more common in glass more common in glass

tubestubes microtainer: plasticmicrotainer: plastic

HematologyHematology

►Evaluating the packed cell volumeEvaluating the packed cell volume►Reference ranges: Reference ranges:

20-40% (reptile)20-40% (reptile) 40-55% (avian)40-55% (avian) 30-55% (mammalian; ferret 45-58%)30-55% (mammalian; ferret 45-58%)

►Buffy coat:Buffy coat: anecdotal used to estimate WBC (mammals)anecdotal used to estimate WBC (mammals) limited samples suggest not usefullimited samples suggest not useful

►Lawton and Divers, 1999Lawton and Divers, 1999

►SerumSerum►appearanceappearance

Hematology:Hematology:

► Total Red Blood Cell CountTotal Red Blood Cell Count Manual techniques: Manual techniques:

►Erythrocyte Unopette Erythrocyte Unopette systemsystem

► ErythrocytesErythrocytes mature cellsmature cells

►ellipsoid with central ellipsoid with central nucleusnucleus

►cytoplasm- orange-cytoplasm- orange-pinkpink

immature cells immature cells ►small, round cellssmall, round cells►basophilic cytoplasmbasophilic cytoplasm

HematologyHematology

►ErythrocytesErythrocytes abnormal shapes and sizesabnormal shapes and sizes

►regenerationregeneration

basophilic stipplingbasophilic stippling►anemia, iron deficiencyanemia, iron deficiency

hypochromatosis-hypochromatosis-►iron deficiency anemia, chronic blood lossiron deficiency anemia, chronic blood loss

HematologyHematology

► Blood parasitesBlood parasites common wild caught common wild caught

specimensspecimens evaluate overall evaluate overall

healthhealth►anemia?anemia?► regenerativeregenerative

Hematology: LeukocytesHematology: Leukocytes

► Circulating pool Circulating pool very largevery large reference rangesreference ranges

►5.0-15.0 x 105.0-15.0 x 1033

Hematology: GranulocytesHematology: Granulocytes

►HeterophilsHeterophils fusiform granulesfusiform granules large round, acentric large round, acentric

nucleus nucleus function-function-

►phagocytosisphagocytosis

heterophiliaheterophilia► inflammation, stress inflammation, stress ►seasonalseasonal

increase summerincrease summer

Hematology: GranulocytesHematology: Granulocytes

► Toxic heterophilsToxic heterophils suggestive of suggestive of

infectious causeinfectious cause indicative of severityindicative of severity changeschanges

►degranulationdegranulation►cell swellingcell swelling►cytoplasmic cytoplasmic

vacuolizationvacuolization

Hematology : GranulocytesHematology : Granulocytes

► EosinophilEosinophil large, round cellslarge, round cells spherical granulesspherical granules nucleus centrally locatednucleus centrally located function-function-

► ParasitemiaParasitemia► AllergyAllergy► InflammationInflammation

seasonal variationseasonal variation► increased winterincreased winter

Hematology : GranulocytesHematology : Granulocytes

► BasophilsBasophils small, spherical cellssmall, spherical cells basophilic meta-basophilic meta-

chromatic granuleschromatic granules functionfunction

►histamine releasehistamine release

Hematology: LymphocyteHematology: Lymphocyte

► LymphocytesLymphocytes small, basophilic small, basophilic

stainingstaining acentric nucleusacentric nucleus functionfunction

►B cells- Ab productionB cells- Ab production►T cells moderate T cells moderate

immune functionimmune function

seasonal variationseasonal variation►decreased in winterdecreased in winter

Hematology: MonocyteHematology: Monocyte

► Largest WBCLargest WBC►cytoplasm- blue-gray cytoplasm- blue-gray

functionfunction►granuloma formationgranuloma formation

HematologyHematology

► ThrombocytesThrombocytes central nucleuscentral nucleus confused with confused with

lymphocyteslymphocytes functions- thrombus functions- thrombus

formation, clot, formation, clot, wound healingwound healing

>200,000 cells/ml>200,000 cells/ml

Injections Injections

►Page 110 L, 159 S, 177 TPage 110 L, 159 S, 177 T►Demonstration Demonstration

Fluid Support Fluid Support

► Ideal fluid is Ideal fluid is hypotonic, non-hypotonic, non-lactated, lactated, balanced balanced electrolyte (e.g. electrolyte (e.g. Normosol R) Normosol R)

►Maintenance fluids Maintenance fluids can be calculated at can be calculated at 20 ml.kg.day. 20 ml.kg.day.

Fluid SupportFluid Support► SQ, ICe, IV, IO, PO are all SQ, ICe, IV, IO, PO are all

effective, choice of route effective, choice of route depends on severity of depends on severity of illness and logistics of illness and logistics of individual animals individual animals

► Always inject between scales Always inject between scales ► Liquid enteral nutrition (e.g. Liquid enteral nutrition (e.g.

Ensure, Sustacal, useful for Ensure, Sustacal, useful for recovery from long-term recovery from long-term anorexia, may be mixed with anorexia, may be mixed with vegetables or fruits for vegetables or fruits for herbivores) herbivores)

► Critical Care Herbivore Diet Critical Care Herbivore Diet by Oxbow Hay Co. or by Oxbow Hay Co. or enterals from enterals from Walkabout Farms

Fluid SupportFluid Support

Pharyngostomy tubes may be needed for Pharyngostomy tubes may be needed for some chelonians some chelonians Force feeding, assist feedingForce feeding, assist feeding

►Force feeding demo. Force feeding demo.

Radiology Radiology

► Lateral, DV, AP Lateral, DV, AP ► Horizontal beam if Horizontal beam if

possiblepossible ► Consider mammography Consider mammography

or dental film or dental film ► GI contrast GI contrast ► IVP- recently described, IVP- recently described,

usefulness needs to be usefulness needs to be determined. determined.

► Page 110 L, 150 S, 175 TPage 110 L, 150 S, 175 T

CheloniansCheloniansWhole-body Craniocaudal Whole-body Craniocaudal

viewview

Venomous snake Venomous snake

Questions? Questions?