Toxoplasma gondii uses cats as its definitive host. Understanding this disease protects both cat welfare and human public health through evidence-based management.
While most cats infected with Toxoplasma gondii remain subclinically affected throughout their lives, immunocompromised cats — those with FIV, FeLV, or on immunosuppressive medication — develop serious clinical disease. Encephalitis causes seizures, behavioral changes, and neurological signs that represent significant welfare harm. Chorioretinitis (ocular toxoplasmosis) causes painful eye inflammation and vision loss. Pneumonia and hepatitis occur in systemic disease. Recognition and treatment of clinical toxoplasmosis provides welfare-improving outcomes in most cases.
The welfare-public health interface is an important dimension of feline toxoplasmosis. Indoor-only cats with no access to prey have minimal infection risk and shed fewer oocysts, reducing environmental contamination. This welfare-compatible management also protects vulnerable human populations — pregnant women and immunocompromised individuals — from oocyst exposure.