swine diseases. confinement rearing and continuous farrowing isospora suis (most common) eimeria ...
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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