What is Toxoplasmosis in Cats?

Toxoplasmosis in cats is caused by a one-celled protozoan parasite called Toxoplasma gondii.

Toxoplasmosis has been found in most warm-blooded animals, including cats. However, the life cycle of the Toxoplasma gondii parasite can only be completed when in the body of a cat. After ingestion of the parasite, usually from prey animals or other uncooked meat, Toxoplasma gondii produce eggs called oocysts. These oocysts are emitted in the cat's feces.

Toxoplasmosis in cats usually causes a minor infection with mild symptoms. Many healthy cats unknowingly harbor the Toxoplasma gondii parasite, becoming carriers of toxoplasmosis, with no ill effects.

However, toxoplasmosis can cause severe problems for young kittens and adult cats who are already infected and ill with other diseases such as feline leukemia or feline immunodeficiency virus. In such cases, symptoms usually include diminished appetite, fever, lethargy and difficulty in breathing. Other symptoms that may occur are loss of coordination, modifications in personality, difficulty in eating, incontinence, seizures, blindness and pneumonia.

Diagnosis of toxoplasmosis in cats is done by means of blood and fecal smear testing. In some cases, microscopic inspection of tissue smears is necessary for a more definitive diagnosis.

Clindamycin, an antibiotic, is the typical treatment for toxoplasmosis in cats. Pyrimethamine and sulfadiazine are also used in some cases. These medications prevent the continued growth of the Toxoplasma gondii parasite. Most cats recover quickly.

Although it is much more common for the Toxoplasma gondii parasite to be transmitted to humans through the ingestion of raw meat, it is possible for humans to contract toxoplasmosis from feces in the cat litter box or other areas.

Just as in toxoplasmosis in cats, symptoms in human victims are usually negligible with the disease becoming acute in only a relatively small portion of the population. Unborn babies of pregnant mothers who are infected with the Toxoplasma gondii parasite are at risk to develop symptoms as they grow up such as blindness, deafness and mental retardation. In addition, those with compromised immune systems due to diseases such as AIDS are particularly vulnerable to toxoplasmosis.

The best way to prevent toxoplasmosis in cats is for you and your cat to refrain from eating raw or undercooked meat.