Toxoplasma

Sheep, goats and all vertebrates (including humans) are intermediate hosts of Toxoplasma; cats are the final host. It is mostly found in cooler climates.

Sheep and goats are infected by ingesting sporulated oocysts from areas of pasture contaminated with cat faeces. Parasites migrate throughout the body and lodge in any of several organs and may also pass to the foetus if the animal (or human) is pregnant. In the tissues they divide within cysts and cause lesions. Cats ingest cysts in sheep or goat meat (or sporulated oocysts from contaminated grass and soil) to continue the cycle.

These are microscopic protozoa and cysts. Sometimes white flecks are found on the placenta in infected animals. To confirm the diagnosis, send the foetus, placenta and serum from unfed lambs or kids to a laboratory. Wear gloves and take precautions when collecting samples.

In sheep, Toxoplasma can cause early or late abortion in ewes having their first lamb. Death of young lambs may also occur. The disease in goats closely resembles that in sheep.

Toxoplasmosis is potentially a human health risk, with effects in the unborn foetus. Immuno-compromised people are at risk. However, there are relatively few cases each year in Australia, although pregnant women should avoid handling cat faeces or raw meat.