11. D/C Protozoa Flashcards
Is giardia zoonotic?
It can be. Pets can have host-specific genotypes as well as zoonotic genotypes of giardia
What is the epidemiology of giardia in pets?
subclinical very common
prevalence - dogs 7-40%, cats 8-10%
risks: yg anims (<1yr), suboptimal enfiro, stressed/immunocompromised, reinfection very common
What is the life cycle of giardia sp?
min dose as low as 10 cysts
PPP 4-16 d
In host, trophozoits attach to enterocytes and divide by binary fission > shedding is intermittent, may last for months > in feces, a few tz million of cysts > in enviro, cysts, survive for months, immediately infective > fecal-oral contact
What are the clinical sign of giardiasis?
most often asymp
diarrhea +/- mucous or fat, rarely blood - may be acute, chronic or recurring
flatulence, vomiting (occasionally), nausea, abdominal pain
lethargy, decreased appetite, weigh loss
Food allergies: dermatitis due to increased permeability of GIT wall to food antigens
How do we diagnose giardia?
only test diarrheic animals or high-risk households
multiple fecal samples (can be intermittent shedding of cysts) - 3 samples over 2-3 day intervals
diagnostic test options:
direct, fresh fecal smear (trophozoits, cysts)
zinc sulfate flotation (cysts)
Elisa snap test (cyst antigen) - test of choice for in clinic
immunofluorescent assay (cyst antigen) test of choice for dx lab
How do we control giardia?
only treat if diarrheic animals or high risk of households
goals of tx: decrease clinical signs and enviro contam - NOT elim of infection, re-testing is not likely to be helpful
inform clients of zoonotic risk (both ways)
sanitation - clean enviro and bathe dog w/ heat, dry, bleach or other disinfectants
metronidazole, fenbendazole and ronidazole
What is the pathogenesis, diagnosis and control of tritrichomonas blagburni
cats <1yr, catteries, carriers
chronic, large-bowel diarrhea
dx by fecal smear w/ saline, culture and microscopy, PCR
no labeled tx (ronidazole, metronidazole
What is the lifecycle of cystoisospora spp lifecycle?
protozoa has asex repro w/ 2 or more rounds for merogony, then there is sexual repro (gametogony) in which an unsporulated oocyst is shed in feces, will become a sporulated oocyst and is then ingested directly, or by PH where it migrates to lymph nodes
What is the pathogenesis of coccifiosis?
pups and kittens (breeders and shelters), often asymp, stress (weaning, concomitant dz), heavily contaminated enviro, destroy epithelial cell in PP
diarrhea, dehydration, poor growth, watery, sometimes bloody, dirrhea (even in PPP)
How do we diagnose and control of coccidiosis?
dx: clinical appearance, fecal float - numbers of oocysts significant
Control: supportive (hydration), enviro decontam
goal of tx: reduce shedding w/ sulfonamides, furazolidone (coccidiostatic), toltrazuril, ponazuril (coccidiocidal)
high risk shelters/kennels, treat dogs at wks 3,5,7
What is the life cycle of toxoplasma gondii?
feline only DH
In ext enviro there is unsporulated oocysts passed in feces, 1-3 days it becomes a sporozoite or sporulated oocyst. IH ingests this or is in feed/water/soil > PPP 2-3wks > IH (chicken, pig, sheep, goat), bradyzoites as cysts in tissues > 3-10d
OR once sporozoites > become tachyzoites and ingested from contaminated food/water. tachyzoites transferred into placenta. OR is excreted as feces and cycle repeats
What is the pathogenesis of toxoplasmosis?
in any cat - 1st time is only time - self-limiting diarrhea, fever, oocysts in feces
transplacental transmission to litter of queen infected for 1st time preg
More severe in congenitally infected kittens - anorexia, lethargy, diarrhea, pneumonia, icterus, encephalitis, ocular lesions (uveitis)
in IH, often asymp; can transmit thru carnivory and vertically
a few host when acutely infected in pregnancy may abort
