Trichomonas gallinae

The protozoan Trichomonas gallinae is a cosmopolitan parasite of pigeons and doves. Other birds such as domestic and wild turkeys, chickens, raptors (hawks, golden eagle, etc.) may also become infected. The disease in pigeons is commonly called canker. The same condition in birds of prey is called frounce. It is believed to be an ancient pathogen causing frounce-like symptoms in dinosaurs.