Extension Spotlight

Toxoplasmosis is a disease that infects one-third of the world’s population, with many people never knowing it. However, the source of the infection might be living in several homes or barns right at this moment. Toxoplasmosis is caused by a protozoan parasite called toxoplasma gondii which has a very complex lifecycle that begins with the common housecat. Interestingly, research suggests that mice or birds that are infected with toxoplasmosis will show neurological complications that makes them attracted to the scent of cats and will make them slower moving.

This increases their likelihood of being caught by a cat which is the goal of the parasite. Once inside the gastrointestinal tract of the cat, the parasite can start reproducing on a large scale. The form that the parasite is in once it reproduces inside the cat is the form that it must be in to infect other species, where it can live. To date, the housecat is the only known place that this type of reproduction can take place.

Once the parasite is shed through the cat’s feces, it can spread to many mammals. If the cat defecates in a litter box, the parasite can infect humans during litter box changes through accidental ingestion. However, if the cat defecates in a barn, pasture, or near feed bags, there is the potential for livestock to become infected. Typically, cattle seem to be resistant to the disease and develop immunity before any signs of infection can develop.

However, sheep, goats and swine can show symptoms of the disease. For each of these species, the disease causes the most problems with pregnant females. The disease can spread from the mother to the fetus through the placenta, meaning it is a congenital disease. The more serious complications take place early into pregnancy where it is common to see spontaneous loss of life with the fetus. The later into pregnancy that the mother is infected, the less serious complications occur for the developing fetus. Lambs, kids, or piglets that are born with congenital toxoplasmosis are likely to be smaller in size and weight and are visibly weaker.

Similar outcomes are true for humans. Women that become infected for the first time during early pregnancy are more likely to suffer a loss of their baby. Infections happening later into pregnancy are likely to cause premature births, lower birthweights, eye damage, motor or developmental delays and enlarged livers or spleens for the infants. Women that are planning to be pregnant should talk to their doctors about toxoplasmosis to learn more.

It is important to know that the disease cannot be spread from animal to animal in sheep, goats, swine or cattle. The parasite is only viable to those animals after it has had an opportunity to reproduce inside of a cat. It is also important to know that livestock cannot infect humans with toxoplasmosis through touch contact. Humans are infected in a few ways with this disease. One example is by eating undercooked, contaminated meat or touching contaminated meat and then not washing hands afterwards.

It is also possible for humans to contract toxoplasmosis if they encounter any item that was exposed to an infected cat’s feces such as soil on vegetables or surfaces around a house. This disease can also be passed from person-to-person in an organ transplant or blood transfusion. Like previously mentioned, one-third of the world’s population has toxoplasmosis, and the disease is not concerning for people other than pregnant women, infants or immune compromised individuals.

Humans should always cook meat to proper temperatures and wash their hands after preparing meat to prevent infection of toxoplasmosis and other zoonotic diseases. It is also important to wash fruits and vegetables before eating them and to clean any surfaces that a housecat might touch.

To prevent infection in livestock, it is important to maintain cat populations and to eliminate cat access to feed and bedding areas. It is also good practice to avoid putting first time mothers on pastures where cats have access during breeding season or early into gestation. The best way to avoid seeing the effects that toxoplasmosis can have on humans and livestock is to use proper management practices and implement good hygiene.