Swine diseases

confinement rearing and continuous farrowing

Isospora suis (most common)Eimeria

carrier sows – source of oocyts piglets 5 days old to weaning

Clinical signs yellow to clear, pasty to watery diarrhea (7-10 days) Dehydration rough hair coat failure to gain weight no blood acidic feces (in contrast

to E. coli) Dehydration

Morbidity is high but mortality is variable, often moderate

Diagnosis Diarrheas in pigs <7days old are not Isospora! Necropsy - fibrinonecrotic enteritis Histopathology - oocysts, merozoites Fecal flotation can be falsely negative

Treatment Adding coccidiostats to feed is ILLEGAL amprolium to piglets

Control - disinfection of farrowing area:◦ Strong bleach or ammonium compounds◦ Between farrowings, steam cleaning

Installation of perforated metal or plastic flooring in the crates will be beneficial in the control of coccidiosis

lower jejunum and ileum.

Reovirus Almost all pigs are infected: species specific Diarrhea in nursing and postweaned pigs Diarrhea appears, usually white to yellow in color

◦ moderate dehydration◦ Vomiting occurs but is not a major clinical sign

Morbidity is variable but mortality usually is low or none when good housing and husbandry is present.

Diagnosis - difficult Necropsy-thin walled small

intestine Histopathology Flourescent antibody test Electron microscopy

Treatment Dextrose and fluids Antimicrobials for concurrent infections

E. coli Isospora

Control Rotaviruses are very stable in the environment:

formaldehyde and chlorine-based disinfectants including chlorox

Wean pigs on good nutritional diet MLV vaccine at 7 and 21 days (in water) and also for

dams

Salmonella typhimurium Salmonella cholerasuis Fibrinonecrotic enteritis or colitis at

necropsy Rectal strictures Culture of organism

Brachyspira hyodysenteriae: Gram-negative, anaerobic spirochete◦ Brachyspira (Serpulina) pilosicoli (similar but less

severe c.s.) Grower / finishers (not in < 3 weeks) Mortality can be up to 30% lagoon water: two months, moist feces: two

months, soil: 18 days Transmission: fecal-oral and fomites, rats,

birds

Clinical signs diarrhea : with gray to

yellow, mucoid feces watery, bloody, mucoid most recover in 2

weeks but 50% may die

Dehydrated: sunken eyes, marked weakness, hollow flanks and weight loss

Large intestine/cecum

SD is a severe disease affecting the colon (large intestine) of pigs causing diarrhoea, frequently mixed with mucus and blood, which can lead to death.

Diagnosis Necropsy - mucohemorrhagic colitis histopathology Spiral shaped organism on

dark field microscopy Culture is definitive

Treatment carbadox, lincomycin (water) and tiamulin

Control Quarantine: 30 – 60 days medicated water, depopulation, close herd vaccine only reduces clinical signs

Lawsonia intracellulare Bent, rod-shaped, Gram-negative bacteria proliferative illeitis, hemorrhagic bowel syndrome

Large intestine: hyperplasia of crypt enterocytes with inflammation and sometimes ulceration or hemorrhage

hamsters, ferrets, guinea pigs, foxes, horses, lambs, rabbits, rats, dogs, white-tailed deer, emus

Weanlings and older Clinical signs

◦ Acute diarrhea with brownish to black unclotted blood◦ pallor, weakness, and rapid death are common; ◦ Subacute to chronic cases occur more frequently in the grower stages

sporadic diarrhea, wasting, and variation in growth rate lesions often include necrotic enteritis and can be easily confused with

salmonellosis.

anemia (think gastric ulcer first) Morbidity and mortality with either

presentation is variable

Diagnosis Necropsy - “garden hose” ilium and colon

can be hemorrhagic or fibrinonecrotic Histopathology - intracellular, silver positive DNA probes

Treatment and control No specific treatment Reduce stress Medicate feed - tylosin, tetracyclines, lincomycin,

tiamulin, and carbadox Live vaccine in water

Trichuris suis pasture 2-6 months of age Large intestine

Clinical signs Anorexia mucoid or mucohemorrhagic diarrhea dehydration, and possibly death of

severely affected animals anemia (2 DDX?)

Diagnosis - fecal float, fibrinnecrotic colitis Control – dichlorvos, levamisole and

fenbendazole

AgentCommon

name

Products

Piperazine PyrantelAvermecti

nsLevamisol

eDichlorvos Fenbendazole

Stephanurus dentatus Kidneyworm - - + + - +

Haematopinus suis Lice - - + - -

Metastrongylus spp. Lungworm - - + + - +

Sarcoptes scabiei Mange mite - - + - - -

Oesophagostomum spp.Nodular worm

+ + + + + +

Ascaris suum Roundworm + + + + + +

Macracanthorhynchus hirudinaceus

Thorny-headed worm

- - - - - -

Stronglyloides ransomi Threadworm - - + + - -

Trichuris suis Whipworm - - - + + +

Salmonella typhimurium Salmonella cholersuis

associated with rectal strictures? Can be large intestine Fibrinonecrotic colitis Rectal strictures Culture

Trichuris suis - colon Ascaris suum - small intestine, milk spots Stephanurus edentatus - kidney Macrocanthorynchus hirudinaceous -small

intestine

Hypoglycemia Streptococcus suis: Gram-positive Salt poisoning Edema disease

Newborn piglets Blood glucose <50mg/dL may develop signs Clinical signs

convulsions shivering hypothermia gait abnormalities

Diagnosis Blood glucose Empty stomach

Treatment 20ml/kg 5% dextrose, warm fluids

Control make sure the milk is flowing

Usually due to water deprivation rather than too much Na

Causes hyperosmalarity of CNS resulting in swelling and edema

Clinical signs thirst, constipation depression, blindness, convulsions

Diagnosis History Clinical pathology-eosinopenia, hypernatremia Histopathology - eosinophilic meningitis

Treatment None

Control provide free access to water reduce salt in diet

Arthritis S. suis, Erysipelothrix, A. pyogenes Mycoplasma hyosynoviae

Myodegenerative disease Malignant hyperthermia (PSE) White muscle disease

Streptococcus suis: gram positive Erysipelothrix rhusiopathiae: gram positive

rod Actinomyces pyogenes May see loss of cartilage Due to fighting, surgical contamination Distended joints, abscesses Penicillin - treatment often no good

Mycoplasma hyosynoviae 4-12 weeks of age acute or chronic lameness non-suppurative arthritis/synovitis edema of synovial tissue Lincomysin to treat

Parvovirus Leptospirosis: gram - spirochete PRRS: Arterivirus Brucellosis: gram negative

100% prevalence: endemic Important signs

◦ large numbers of mummified fetuses◦ increase in the number of returns to estrus◦ small litters◦ failures to farrow, decreased farrowing rate,◦ rarely abortion

Transmission: secretions, oro-nasal, transplacental

Poor conception rates, reabsorbed litters, mummies and small litters

Transient leukopenia Signs depend on time of infection

<30days - embryo resorbed 30-70days - mummy >70days - dead or weak, survive normally no other signs of illness

SMEDI - stillbirth, mummy, embryonic death, infertility

Diagnosis - detection of virus in mummy by immunofluorescence or by rising titer

Control◦ Resistant to environmental degradation and many

disinfectants◦ Natural infection of gilts before breeding◦ Commingle gilts with sows◦ Grind up mummies and feed to gilts◦ Vaccination!

Killed vaccine: breeding animals may still get some losses

Leptospirosis◦ Leptospira interrogans (serovars pomona,

icterohaemorrhagiae, canicola, and bratislava)◦ Leptospira borgpetersenii (serovars sejroe and

tarassovi) ◦ Leptospira kirschneri (serovar grippotyphosa)◦ serovar L. hardjo :bovines and has been reported

to infect pigs in close proximity Zoonosis

CS◦ Adult: mild fever and

inappetence for a few days, last trimester abortion, stillbirths, weak litters,

◦ Piglets: fever, anorexia, hemolytic anemia, hemoglobinuria, icterus, convulsions in occasional pigs and a failure to grow and gain weight and sudden mortality in piglets

Placentitis

Diagnosis Culture difficult Dark field microscopy

of fetal fluids, urine Serology (<1:800) Necropsy: interstitial

nephritis or generalized kidney scarring which may only be noticed at slaughter as “white-spotted kidneys

Treatment Chlortetracycline in feed/ oxytetracycline, tylosin,

and erythromycin Control

Vaccination Gilts twice before first breeding Sows before every breeding

Rodent control

Porcine reproductive/respiratory syndrome◦ Arterivirus

Premature farrowing Small weak piglets or stillborns increased numbers of mummies Delayed or abnormal estrus Serology to diagnose Vaccination for prevention

Abortions, mummies and weak pigs

Brucella suis: gram negative Zoonotic Ist agent to be weaponized by US ~ 1950 Rare in US

◦ A cooperative, 3-stage, State-Federal-Industry eradication program was initiated with a goal of eradication of brucellosis.

◦ Goal is nearly accomplished in domestic herds, but feral swine remain a reservoir in the US.

Transmission: direct contact◦ ingesting aborted fetuses, fetal membranes or

fluids discharged at the time of abortion Clinical signs

abortion at any time in gestation infertility - many sows coming back into heat

(abortions in first trimester) infected sows recover and deliver normally

Lesions mild endometritis arthritis orchitis

Lesions in the uterus of a pig caused by B. suis

Diagnosis The buffered, acidified plate antigen (BAPA) test and

the standard card test (SCT) have been used extensively as presumptive test

confirmation, either the standard tube test (STT) or the particle concentration fluorescence immunoassay (PCFIA)

Culture: most accurate Treatment and control

◦ Test and slaughter (depopulate ~ 2-3 months)

Parvo virus PRRS Pseudorabies Lepto

http://www.aphis.usda.gov/animal_health/animal_dis_spec/swine/

http://www.ncsu.edu/project/swine_extension/ncporkconf/2002/roberts.htm

http://www.vetmed.wisc.edu/pbs/zoonoses/Erysipelas/erysipelasindex.html

http://vetmed.iastate.edu/vdpam/new-vdpam-employees/food-supply-veterinary-medicine/swine/swine-diseases/haemophilus-parasuis-

http://vetpath.wordpress.com/category/necropsy-cases/

http://www.fmv.utl.pt/atlas/figado/pages_us/figad015_ing.htm

http://www.cfsph.iastate.edu/DiseaseInfo/disease.php?name=influenza&lang=en

http://microgen.ouhsc.edu/a_pleuro/a_pleuro_home.htm

http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/51205.htm&word=leptospirosis%2Cin%2Cpigs