Avian trichomoniasis is caused by a single celled protozoan, Trichomonas gallinae, and is a common parasite of doves and pigeons. Other birds such as domestic and wild turkeys, chickens, and raptors (e.g., hawks, golden eagle) may also become infected.  In doves and pigeons, the parasite is generally confined to young birds.  Parasites are transmitted from adults to squabs in the pigeon milk produced in the crop of the adult.  The parasite can also be transmitted through feed when infected birds regurgitate contaminated food and orally at birdfeeders and waterers.  Birds of prey can become infected by feeding on infected birds. 

The infection is spread from bird to bird and the resulting infection may be asymptomatic or may be fatal.  Infected birds experience weight loss, appear listless, and stand grouped together.  Yellowish lesions may be seen around the beak or eyes of mourning doves and the face may appear “puffy”.

Trichomoniasis is a frequently diagnosed disease of mourning doves.  Many outbreaks are associated with heavily used, contaminated bird feeders.  Proper maintenance and cleaning of feeders can greatly reduce the transmission of this disease.