adults: most immune. Can shed in feces but be asymptomatic
Transmission of coccidia
host-specific. Canines will not infect felines, etc, neither infect humans. (crypto)
Coccidia environmental factors
sporulated oocysts (96hrs after shedding) can survive a year in moist, protected environment.
Killed in freezing or high temps
sporulation at 20-40 C
coccidia form, non pathogenic to animals (just carried)
diagnosis of coccidia
based on signalment, history, clinical signs and oocytes present in feces.
Oocytes are not definitive, could be pseudoparasite
looks like isospora, is non-pathogenic to dogs.
parasite of deer and rabbits.
Treatment of coccidia
Sulfadimethoxine (Albon): ONLY drug approved
Ponazuril: newer drugs, off-label, may be effective
Albon, used in coccidia. (also Ponazuril)
new drug, off-label for Coccidia
Felines ONLY DEFINITIVE HOST
any warm blooded animal intermediate host
most important coccidian parasite
where parasite can perform sexual reproduction
Life cycle of toxoplasma gondii (both intermediate and definitive)
Cats infected by ingesting TISSUE of infected intermediate host (rodent or bird)
Toxo penetrates intestinal wall and repicates throughout body as tachyzoites (extra-intestinal cycle) (non-sexual)
Same time, invade and replicate within intestinal epithelial cells (entero-epithelial cycle), culminating in sexual formation of unsporulated oocysts, shed for 7-10 days one time in life
immune response, shedding and tachyzoite stops, bradyzoites formed, contained in tissue, remain for life
oocysts sporulate in 24-72 hours in soil or vegetation
mammals and birds ingest oocysts
penetrates small intestinal mucosa, multiplies in cells
spreads through body in lymph and cascular systems, tissue cysts with bradyzoites in many tissues (no oocyte production)
cat eats tissue of intermediate host or sporulated oocyst
toxoplasma life cycle, when organisms penetrate intestinal wall and replicate throughout body as tachyzoites (no sexual reproduction)
toxoplasma life cycle, when organisms invade and replicate within intestinal epithelial cells. Culminates in sexual reproduction, formation of unsporulated oocysts which are shed for 7-10 days in feces
bradyzoites and tachyzoites
toxoplasma life cycle.
tachyzoites: extra-intestinal cycle, small crescents, only present in definitive host (feline)
bradyzoites: post-immune response in cat or in intermediate host, cysts full of organisms contained in tissue that stay forever.
transmission of toxoplasma
ingestion of infected mammalian or avian tissue (undercooked meat like pork)
ingestion of sporulated oocysts (feline feces, soil, water, vegetation)
transplacental or transmammary transmission of TACHYZOITES, so must be recent infection
clinical signs of toxoplasma
most asymptomatic, young more likely to show signs
chorioretinitis (lesions in eye)
diagnosis of toxoplasma
fecal float: rarely see animal during shedding, so limited use
antibody assays: shows infection, not whether it is current or past
Serum: seronegative when shedding oocytes, seropositive after the fact. If seropositive, NOT SHEDDING
titers: NOT SHEDDING. shows exposure/immunity (positive IgG), recent/active infection (IgM), active infection if symptomatic, look for fourfold increase in IgG in paired titers (recent infection)
Treatment of toxoplasma
Clindamycin hydrochloride for 2-3 weeks.
Transmission of human toxoplasma (5)
ingestion of sporulated oocysts (only infected if sporulated): 1. cat feces in litter for 24-72 hours, fecal-oral
2. contact with oocyst contaminated soil (gardening and playing in soil)