Protozoa Flashcards
What are the definitive hosts of Giardia species?
dogs (G. duodenalis) and cats
- referred to as “assemblages” that can infect different animals
What are some common clinical signs associated with Giardia infection?
- diarrhea + other signs of colitis
- weight loss, anorexia
How is Giardia transmitted?
fecal-oral by ingestion of cyst
- contaminated water or feces
- thorough self-grooming
- fomites
- NO INTERMEDIATE HOST
What are 4 options for diagnosing Giardia infections?Why is diagnosis commonly difficult?
- direct smear using a saline mount
- fecal flotation using centrifugation
- fecal Giardia ELISA for antigen detection
- PCR
intermittent shedding of organisms is common –> repeated and various types of tests recommended
What are the 2 most common treatments for Giardia infection?
- Fenbendazole
- Metronidazole
- re-test after medication period to ensure there is no evidence of treatment failure
(not technically approved)
How can Giardia infections be reduced? Is it zoonotic?
cysts are resistant in the environment, so environmental control is important
not established
What are the domestic small animal hosts of coccidia?
- CATS - Cystoisospora felis, C. rivolta
- DOGS - C. canis, C. ohioensis, C. neorivolta, C. burrowsi
Eimeria spp. are not true parasites –> considered a pseudoparasite
What clinical signs are associated with coccidiosis in dogs and cats?
- diarrhea and other signs of colitis
- weight loss
- dehydration
How is coccidiosis transmitted?
fecal-oral
- ingestion of infected sporulated oocysts from the environment
- ingestion of infected transport hosts
How is coccidiosis diagnosed?
fecal flotation
What is the only approved treatment for coccidiosis? What are 2 other not approved options?
Sulfadimethoxine
- Ponazuril
- TMS
What is the most common cause of Tritrichomonas infection in cats? Where do they reside?
T. blagburni
colon and cecum of cats
How is Tritrichomonas infection transmitted?
fecal-oral
What clinical signs are indicative of Tritrichomonas infection in cats?
- chronic/intermitted diarrhea
- other signs of colitis
What are 3 diagnostic options for Tritrichomonas infection in cats? How can they be differentiated from Giardia?
- direct fecal smear
- PCR
- culture
T. blagburni has random and jerky movements while Giardia has more of a “falling leaf” movement
What treatment is most commonly used for Tritrichomonas infection?
Ronidazole - not technically FDA approved
- neurotoxicity side effects and resistance are possible!
What is the domestic small animal host of Toxoplasma gondii? What are 3 modes of transmission?
cats
- ingestion of infective oocysts
- ingestion of infected tissue containing bradyzoites
- passage of tachyzoites from dam to offspring via transplacental or transmammary transmission
What are 3 diagnostics used for Toxoplasma gondii infection?
- fecal flotation - recovers oocysts, limited usefulness
- IFA, ELISA - rise in IgG over 2-3 weeks or high IgM
- PCR
What are 3 treatment options for Toxoplasma gondii infection?
- Clindamycin - treatment of choice
- Trimethoprim-sulfonamide
- Pyrimethamine + sulfonamide
What significance does Toxoplasmosis in cats have in humans?
serious zoonotic risk that can cause congenital defects
- pregnant women must avoid contact with soil, cat litter, raw meat, and cats excreting oocysts
What is the domestic small animal host of Neospora caninum? What are 3 methods of transmission?
dogs
- ingestion of infective sporulated oocysts
- consumption of cattle tissues containing bradyzoites
- transplacental transmission of tachyzoites from dam to offspring
What are the clinical signs associated with Neospora caninum infection in younger and older dogs?
YOUNG - ascending paralysis
OLD - neurologic, respiratory, and/or dermatologic signs
What are 4 options for diagnosing Neospora caninum infection?
- fecal flotation - recovers oocysts, rarely detected
- IFA, direct agglutination, ELISA - rise in IgG over 2-3 weeks or high IgM
- PCR
- cytologic or histologic exams
What 2 treatments are recommended for Neospora caninum infection?
- Clindamycin
- Trimethoprim sulfadiazine + pyrimethamine
What Cryptosporidium species infect dogs, cats, and ruminants?
DOG = C. canis
CAT = C. felis
RUMINANT = C. parvum
How is Cryptosporidium transmitted? What are 4 options for diagnosis?
fecal-oral via sporulated oocysts
- complete fecal examination - fecal float + direct smear, due to shedding pattern it may be of limited diagnostic usefulness
- ELISA
- fluorescent antibody tests to visualize oocysts in feces
- molecular methods done in special labs
What are 4 possible treatment options for Cryptosporidium infections?
- Nitazoxanide (Alinia)
- Paromomycin
- Tylosin
- Azithromycin
