An outbreak of toxoplasmosis in an aviary collection of Nicobar pigeons (Caloenas nicobaria).

Abstract

Three out of 10 Nicobar pigeons (Caloenas nicobaria) in an aviary collection in South Africa were found dead with no presenting clinical symptoms. Histological examination of formalin-fixed tissues from all these birds revealed necrotic foci in various visceral organs (liver, spleen, heart, kidney and lungs), plus diffuse pulmonary congestion and oedema with vasculitis. Numerous protozoal tachyzoites were present in all organs and there was strong positive immunohistochemical (IHC) labelling of these organisms for Toxoplasma gondii. Pathology was consistent with acute systemic toxoplasmosis as a consequence of oocyst ingestion. Feral cats were known to be a problem at the facility. Clinical toxoplasmosis is rarely reported in pigeons and this is believed to be the 1st report of toxoplasmosis in Nicobar pigeons.