In Practice 21: 578-589 (1999)
© 1999 British Veterinary Association

Feline toxoplasmosis

¹ The College of Veterinary Medicine and Biomedical Sciences at Colorado State University The Toxoplasma gondii Serology Laboratory

TOXOPLASMA GONDII infection is extremely common throughout the world. The seroprevalence in cats and humans varies by region and country, but is often around 30 to 40 per cent. Once infected with T gondii, the organism probably remains in the tissues of cats and humans for life. It is generally recognised by the medical profession and by many lay people that cats are ultimately responsible for the maintenance of T gondii in the environment by passing oocysts in faeces. Clinical toxoplasmosis can be severe in transplacentally infected children and in other immunosuppressed people and, hence, veterinarians are commonly consulted to determine the fate of individual cats due to the potential zoonotic risk. It is possible that some cats are euthanased needlessly because of a misunderstanding of the biology of the organism. The clinical manifestations in cats infected with T gondii are diverse, with both fatal and sublethal syndromes being recognised. However, definitive diagnosis can be difficult, and it is possible that many cases of clinical feline toxoplasmosis are misdiagnosed. It is, therefore, extremely important that veterinarians understand T gondii infection in cats for both zoonotic and clinical reasons. The aim of this article is to present an overview of the current clinical and zoonotic issues associated with feline toxoplasmosis.