Toxoplasmosis (Toxoplasma gondii) in Cats Symptoms and Treatments

Toxoplasmosis, a disease of cats and other mammalian species, is caused by a parasitic protozoan, Toxoplasma gondii. Protozoa are single-celled organisms that are among the simplest creatures in the animal kingdom. Although infection with Toxoplasma is fairly common, actual disease caused by the parasite is relatively rare.

Diagnosis usually involves a routine blood test. Your veterinarian could also examine a stool sample, although this would only offer a diagnosis if the cat was shedding oocysts at the time. Also, the oocysts could be mistaken for another parasitic infection, so a blood sample is the best & most accurate way to diagnose toxoplasmosis.

Most cats don't show outward signs of infection. Although some cats will show clinical symptoms such as lethargy, loss of appetite, fever. Symptoms most often occur in kittens & young cats.

More severe symptoms may also include inflammation in the eye, pneumonia, hepatitis (inflammation of the liver), causing vomiting & diarrhea, enlarged lymph nodes.

The two drugs that are most often used—pyrimethamine and sulfadiazine—act together to inhibit Toxoplasma reproduction. Treatment must be started as soon as possible after diagnosis and continued for several days after signs have disappeared. In acute illness, treatment is sometimes started on the basis of a high antibody titer in the first test. If clinical improvement is not seen within two to three days, the diagnosis of toxoplasmosis should be questioned.

Pyrimethamine may be unpalatable or toxic to some cats, even if given in small amounts. Recently, the antibiotic clindamycin has been reported to be effective in treating feline toxoplasmosis, with few side-effects observed.

No vaccine is as yet available to prevent either Toxoplasma infection or toxoplasmosis in cats, humans, or other species. Research in this area is in progress. As prevention, keep cats indoors and do not allow them to hunt rodents and birds. Feed cats only cooked meat or processed food from commercial sources.

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