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12 Cards in this Set
- Front
- Back
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Intestinal Cryptosporidium
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C. parvum - most imp
- Genotype 2 - Young cws (Older - C. bovis) - Genotype 1 - C. hominis, anthroponotic Develop in entercyte microvillious border NOT in host cell cytoplasm Merogony, gametogony, sporogony - all in SINGLE host, asexual stages continue in host until immune response - oocysts immed infect to new host - sporulated oocyst has 4 naked sporozoites - Thick shelled oocyst - passed in feces - Thin-shelled - autoinfective Variable D+, fever, anorexia pos, Dehyd (met acidosis pos) Dx - Oocysts in fecal float w/sugar - Small, 1-4 dots, pink, refractile Stained fecal smear, GI impression smear Tx- suppurative care, prophylactics to decrease shedding/sign severity Water purifiers not helpful, repeated freeze/thaw can kill, boiling |
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Sarcocystis - Herbivore Phase
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Obligate indirect w/ 2 hosts
- Carnivore - definitive (no signs), Herb/omnivore - intermed (more narrow range, signs develop) Intermed- Ingest sporulated oocyst -> Merogony Vascular phase - sporozoites into endo cells of bv - 2 more cycles follow, 4-5 weeks Signs: Fever spikes, anemia, abortion,CNS, death Muscular phase - merozoites in last merogony cycle initiate - Skel/card muscle, sometimes nerual tissue - Mult in immature non-infect cycsts (metrocytes) - Become infective cysts w/ bradyzoites in muscle Signs - Myositis, myocarditis, CNS, hair loss |
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Sarcocystosis - Carnivore Phase
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Ingestion of bradyzotes from mature cysts
- Infect enterocystes -> gametogony, make oocysts - Oocyst sporogony in gut, sporocysts shed in feces, imed. infect Asymptomatic |
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Sarcocystosis - Dx,Tx
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Dx: Herbivore: postmortem histology
- Schizonts in vasc of major organs, cysts in muscle/CNS Carnivore - Fecal float fresh feces - Sporulated oocysts looks like 2 sporocyst w/membrane Tx - Amprolium - Dont let dog/cat eat raw meet - no dog/cat feces in herbivore food/water |
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Equine Protozoal Myeloencephalitis
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Sarcocystis neurona - primary
- High intermed host range - Most subclinical Only in Americas Risks: Opossums on farm, woods on farm, previous health stressor, wood chip bedding Signs - Asexual mult in CNS + inflamm -> CNS disease - Proressive Asymmetric Ataxia/Focal Muscle Atropy common Dx - No gross lesions, histo - parasites in CNS w/inflamm - CSF western blot - lumbosacral space Tx - Pyremethamine, Ponazuril Prevent - No opposums pooping in feed, remove dead bodies, prophylactics |
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Toxoplasma gondii
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All warm-bloodeds, Felids definitive
Ingest sporulated oocysts from cat feces, ingest bradyzoites from tissue cysts, transplacentally IH - Only extra-intest replic as tachyzoites, no oocyst sheding Cats: Merogony in GI epith, Gametogony only in cats, and only they shed oocysts in feces - Unsporulated, will do so in 1-5 days - Extra-intestinal rep as tachyzoites in almost any cell in body Cysts break down -> release bradyzoites ->Tachyzoites-> elim by immune, but mult in immune compromised |
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Toxoplasmosis signs
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Felids- asympt usually
Kittens - infected post-weaning, maternal Ig decline, begin hunting Cats usually shed oocyst only once in lifetime following 1st infection - Tachyzoites mult - necrosis, inflamm in organ systems Dogs - Uncommon Small ruminant - If female has primary infect during gestation - Can cause abortion - Adults: slight fever only sign Swine - Neonatal (gotten after birth) - Weakness, anorexia, fever Cattle/horse/camelid - Resistant, disease rare |
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Toxoplasmosis - Human Signs
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Immune-competent: Flu-like
Congenital - severity depends on when infected Immune compromised - encephalitis |
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T. gondi - Dx
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Cats only - fecal float to find oocyst
Cat/interm -extra-intestinal tachyzoites or cysts w/bradyzoites Serology - IgM response, rising titer Small rum- repro decreae - Grey/white lesions in cotyledons - Anti-toxoplasma Ig in fetal fluids - Histopath - fetal brain/placenta Tx - clindamycin, pyremethamine, (tachyzoites not bradyzoites) |
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Neospora caninum
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Dogs - only known definitive host
Intermed Cow, also goat, dog, sheep, horse Horizontal - Intermed ingest sporulated oocyst, Defin host ingests tissue w/bradyzoites Also Vertical - Transplacental tachyzoited from dam to offspring (cow, dogs) Dog - Intestinal merogony, gametogony. Non-sporulated oocyst shed in feces - Extra intestinal (all hosts) asexual rep va tachyzoites (clinical signs, transplacental trans) - Become bradyzoites via immune response, form cysts in CNS/retina - Thicker wall than Toxoplasma Congenital - leg weakness, ataxia -> paralysis (UMN), joint fixation Dogs w/clinical signs not shedding Dx- serology, ident parasite in tissue Tx - clindamycin, pyremethamine - Stops progression, wont reverse hyperextension |
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Bovine neosporosis
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Major cause of abortion
- fetal death/mummification, abortion, life calf with congenital infec (CNS problems,most common, dies) Cows asymp but seroposiitve, subseq pregnancies often effected Dx - herd history, signs, non-supp necrosis in fetal brain, musc, placenta Both species - successive litters can be infected from same mom |
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Hepatozoon americanum
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American canine hepatozoonosis
- emerging, transmitted by Gult Coast Tick, related to H. canis Tick - definitive host/vetor. Zygote/sporogony Canine - intermed. Eat tick. - Merogony (tissues), gemetogony (macros) - Naturally infected coyotes seen Tick - eats gamonts from macro in bld, sporulated oocysts in tick hemocoel Dog - eat tick w/oocysts, sporozoite infects macro (may be in tissue) - develops "onion skin cysts" - parasite in cell surrounded by mucopolysaccharide - Merogony within cyst btwn muscle cells, gamonts develop in monocytes Signs - fever myalgia, myasthenia, wasting, periosteal bone prolif Dx - X-Ray (bone prolif), muscle biopsy we/meronts/myositis , gamonts in bld Tx - No cure. Trimeth/pyre/clin w/ NSAID to reduce fever reduce signs |
