Sometimes cats are infected with a parasite called Toxoplasma gondii. In its simplest form, this infection in cats is a lot like the infection caused by coccidia. The cat becomes infected by swallowing cysts that are in soil or other substances containing the forms of the Toxoplasma gondii organisms that resist nature. Then, more adult stages of the parasite develop in the wall of the cat’s intestine and eventually produce more cysts that pollute the cat’s surroundings in its own feces.

Cats can also become infected by hunting.  If birds or mammals swallow the cysts passed in cat feces, stages of the organism multiply in their tissues and stay in their bodies for their whole lives. If cats eat these carriers (“hosts”), the same stages of the Toxoplasma gondii are also capable of infecting the cat.

The greatest concern with toxoplasmosis is that cysts released into the surroundings can infect people. Toxoplasma gondii infection is a moderately frequent event in people. In the United States, approximately 10% to 20% of people have the organisms in their bodies in much the same way that birds and rodents do. These organisms do not usually cause disease in the infected human beings. 

There are two times, however, when the organisms can be dangerous to people:

One is when the disease occurs in people because their immune system is somehow damaged by other diseases or weakened by the use of drugs given to control other medical conditions. In those situations people can become very ill due to the rapidly multiplying organisms in their bodies. 

The second dangerous situation occurs in women who are pregnant. A Toxoplasma gondii infection can have severe consequences for a developing baby if the mother is infected with toxoplasmosis for the first time during her pregnancy.  The disease in the growing baby and, later the child, can show up as severe generalized illness, as eye disease, or it may actually remain hidden.

Cats that are infected with Toxoplasma gondii usually do not have any signs of infection, although they may sometimes have diarrhea or soft feces accompanying the intestinal phase of the disease. In cases where cats develop generalized toxoplasmosis, the infection may show as serious general disease that may be associated with damage to the intestinal wall, liver, lungs, or nervous tissue. Some cats develop eye lesions.

Toxoplasma gondii infections can be prevented by removing your cat’s feces regularly from where the cat defecates (be sure to wear gloves or use a long-handled scoop to avoid touching the litter when doing this). Cats also need to be prevented from hunting because they can get this infection from eating small birds or animals infected with the tissue stages of the parasite.

Read the CDC brochure for cat owners about toxoplasmosis (note: you must have Adobe Reader to open and read this file).

Lakeside Veterinary clinic assumes no liability for injury to you or your pet incurred by following these descriptions or procedures.