Direct life cycles Flashcards
What is the life cycle of eimeria?
Host ingests sporulated oocyst.
Sporozoites are released and enter the epithelial cells of the gut.
Undergoes 1 or more cycles of schizogony and gametes fuse to form oocysts.
Unsporulated oocysts are passed into the environment and are adapted to persist here.
Oocysts require warmth, moisture and oxygen to sporulate in the environment,
What 3 factors does disease depend upon?
Parasite factors
Host factors
Environmental factors
What are the clinical signs of eimeria infection?
Bloody diarrhoea
What is the pathology associated with eimeria?
Thickened mucosa, inflammation, haemorrhage, necrosis
How can eimeria be diagnosed?
Faecal egg count
What is the life cycle of cryptosporidium parvum?
Thick walled sporulated oocyst leaves the host
Contamination of water and food supplies
Thick walled oocyst is ingested by the host
What are the clinical signs of cryptosporidium parvum infection?
Anorexia
Diarrhoea
What are schizonts?
Located in the brush border
Parasite develops between the cytoplasm and cell membrane within parasitophorous vacuoles and is covered by host microvillous membranes
Infected microvilli are destroyed with the parasite leaves the cell.
What causes malabsorptive diarrhoea of a giardia lamblia infection?
Trophozoites attach to the surface of epithelial cells to prevent absorption.
Where does the giardia lamblia cyst mature?
Colon and faeces
Where does excystment of giardia lamblia occur? What is released?
Duodenum.
Trophozoite.
How is tritrichomonas foetus transmitted?
Sexually
What are the clinical signs of a tritrichomonas foetus in a bull, cow and cat?
Bull - asymptomatic
Cow - infertility, abortion, early foetal death, foetal maceration, pyometria, vaginal discharge
Cat - typhlocolitis, inflammation of the colon.
How is spironucleus meleagridis/columbae transmitted?
Faeco-oral transmission
What is the pathology associated with a spironucleus meleagridis/columbae infection?
cattarhal enteritis in turkey poults and game birds
What is the ley term for histomonas meleagridis?
Black head - chickens and turkeys
What is the route of direct transmission for histomonas meleagridis?
faeco-oral
What is the indirect route of transmission for histomonas meleagridis?
By heterakis gallinarium, which invaded by histomonas meleagridis.
Histomonas is found within heterakis gallinarium eggs.
Heterakis eggs are passed in the faeces.
Worms/birds ingest heterakis eggs.
Worms/birds are ingested by the host.
