Neospora, Sarcocystis, Besnoita

Front 1

What are the life stages/cycles of Neospora caninum? Who is the definitive host? What about intermediate hosts?

Back 1

- dogs are the definitive host, they ingest tissue cysts from contaminated intermediate hosts
- int. hosts include cows, horses, small ruminants
- unsporulated oocysts pass in the feces and they sprorulate in the environment
- the oocysts are ingested by intermediate parasites and they become tissue cysts in this host
- if a cow becomes pregnant or contracts when pregnant, tachyozoites are transmitted through the placenta after the tissue cyst stage

Front 2

What are the clinical signs and problems associated with N. caninum in dogs and intermediate hosts? What about treatments?

Back 2

- N. caninum is a major cause of abortion in dairy cattle, no treatments, must cull infected cows with repeat abortions
- causes neonatal diseases in dogs including CNS symptoms, generally contract from mom that doesn't have symptoms, entire litter can be infected
- treatment of female dogs doesn't prevent transmission, can try to treat puppies that show symptoms especially neonatal paralysis
- must stop breeding female dogs
- causes CNS signs, abortions, and congenital infections in horses

Front 3

What is the name of the Neopspora common to horses and how is it different? What problems does it cause?

Back 3

- N. hughesi, really the same as N. caninum
- abortion in mares, neonatal paralysis in foals
- uncommon

Front 4

Where is Besnoitia found and what animals does it commonly infect?

Back 4

- emerging dz in Europe found in tissue cysts of connective tissue
- found in donkeys, opossum, cats

Front 5

What is the life cycle of Besnoitia darlingi and what animals does it involve?

Back 5

- definitive hosts is the cat, oocysts are passed in cat feces and become infective in few days
- opossum drinks/eats from contaminated sources
- becomes tachyzoites in intestine, then enters tissue and become tissue cyst bradyzoite

Front 6

Who does Sarcocystis infect and what is the life cycle?

Back 6

- Sarcocystis spp. MUST have two hosts, and infects the muscle
- Carnivores/omnivores are definitive hosts generally, they excrete sporocysts into the environment
- intm. hosts are usually herbivore or omnivore
- infective intm. host tissue is eaten by definitive host (dogs especially) which is the way dogs become infected

Front 7

What are the symptoms/clinical signs of Sarcocystis infections?

Back 7

- generally not associated with diarrhea, typically non-pathogenic
- in cows it can cause abortions and abnormal capillary flow
- may also cause systemic dz and encephalitis in dogs

Front 8

What is the agent that causes EPM in horses and what are the clinical signs?

Back 8

- Sarcocystis neurona
- causes CNS signs in horses
- can sometimes cause enteritis as well

Front 9

What is the definitive and intm host of S. neurona? What category to horses fall under?

Back 9

- opossum is definitive host
- cats, armadillos, racoons, mink, and skunks are true definitive hosts
- horses are technically an intm. host but they are an abnormal host

Front 10

What is the life cycle of S. neurona? How do we diagnose?

Back 10

- S.neurona unergoes schizongy and releases merozoites which rupture cells and damage tissue in the CNS
- dx is best made with western blot using CSF because this indicates an active infection, the problem with serum is that this indicates Ab's and therefore exposure only

Front 11

Describe the life cycle and animals infected by S. falcatula?

Back 11

- definitive host includes the opposum
- intm. but abnormal hosts includes pet birds
- the parasite matures in the small intestine, sporulated oocysts are excreted in the feces and ingested by birds
- S. falcatula undergoes schizogony in birds and is deadly