toxoplasmosis blood parasite, toxoplasma gondii domestic and wild cats = definitive host british...

Toxoplasmosis• blood parasite,

Toxoplasma gondii

• Domestic and wild cats = definitive host

• British Columbia = cougars

Toxoplasmosis

• Intermediate hosts– Moose– Pronghorn– Mule deer– WTD– Black bear– Red fox– Skunks– Opossum– Mink– Small mammals

Neosporosis

• blood parasitic protozoan, Neospora caninum

• Definitive hosts = canids

• Intermediate hosts = livestock

• Dogs deposit feces into pastures or food stuffs or water

Neosporosis

• Forms cysts in the tissue and remains dormant as bradyzoites. Dogs that eat infected meat from deceased cattle will ingest the bradyzoites and become infected, thereby shed more Neospora caninum oocysts.

Neosporosis

• fetal abortions, stillbirth, low milk yield, reduced weight gain, weakened condition, premature culling in cattle

• economic loss to farmers

Neosporosis• Woodbine et al. (2008) BMC

Veterinary Research. 4:1471-8219 • seroepidemiological study of N.

caninum antibodies in England with 29,782 samples of blood taken from 15,736 cattle from 114 herds visited on three occasions at yearly intervals.

• 94% of herds had at least 1 seropositive cow; 12.9% of adult cattle had at least 1 seropositive test.

• 90% of herds were seropositive at all visits

• median seroprevalence in + herds was 10% (range 0.4% to 58.8%).

• positive association between the serostatus of offspring and dams that were ever seropositive.

• Between-herd movements of infected cattle enhance spread, particularly into low seroprevalence herds.

Neosporosis

• >40% of white-tailed deer sampled from Illinois exhibited antibodies to Neospora caninum

• Seroprevalence in WI wildlife species:– 19.0% WTD– 14.7% coyotes – 11.1% foxes – 0% raccoons & opossums

Neosporosis

• Transmission from deer & cattle to dogs & coyotes – demonstrated

• Incidence of Neospora higher where high cattle densities and high numbers of wild canids

Neosporosis* Potential for crossover

Sarcocystosis

• Nonfatal infection, primarily in birds (waterfowl)

• Dabbling ducks• Adult birds• Intermediate host =

bird (asexual stage)• Definitive host =

mammalian carnivore (sexual stage)