An outbreak of sarcocystosis in psittacines and a pigeon in a zoological collection in Brazil.

This report describes an outbreak of acute pulmonary sarcocystosis in different species of captive psittacines and in a Luzon bleeding-heart pigeon (Gallicolumba luzonica) in a zoological collection in Brazil. A majority of the birds were found dead and had exhibited no previous clinical signs. Grossly, pulmonary congestion and edema were the most-common findings. Enlarged and congested livers and spleens were also frequently observed. Microscopically, there was edema, fibrin exudation, congestion, and perivascular and interstitial lymphoplasmacytic infiltration associated with numerous sinuous schizonts of Sarcocystis sp. in the lungs. Mild to moderate myocarditis, hepatitis, splenitis, and interstitial nephritis were also observed in the birds. Immunohistochemistry confirmed Sarcocystis sp. in the capillaries of lungs, hearts, livers, and spleens of most of the birds, but also in the pancreas, kidney, intestine, proventriculus, and brain of a few birds. The probable source of Sarcocystis sp. in these birds was the wild opossum (Didelphis albiventris), a common inhabitant of a local forest that surrounds the Belo Horizonte Zoo (Fundação Zoo-Botânica). This is the first documentation of Sarcocystis infection in psittacines and a pigeon from Brazil.