Toxoplasma gondii is a widespread parasite with cats as its definitive host, raising welfare and public health questions in companion animal management.
Toxoplasmosis welfare considerations span both cat and human health. Cats experiencing acute clinical toxoplasmosis suffer from pneumonia, neurological symptoms, and uveitis (eye inflammation) — all significant sources of suffering. Immunocompromised cats — those with FIV or FeLV — are at much higher risk of clinical disease. Most infected cats, however, shed oocysts asymptomatically, representing limited direct welfare harm to the cat. The welfare implications extend to public health management: unfounded fear of cat-borne toxoplasmosis has led to unnecessary cat surrenders and euthanasia, harming both cats and the human-animal bond. Education about actual transmission risk — the greatest human exposure is from undercooked meat, not cat contact — is essential to preventing welfare harm from misinformation. Indoor cats that do not hunt prey have minimal infection risk.