Pigeon Canker (Trichomoniasis) Canker in pigeons is called Trichomoniasis in medical science. It is caused by a protozoan parasite and is especially common among young pigeons (squabs). Symptoms of Canker 🐦 White or yellowish lumps/lesions inside the mouth and throat – looks like curd or lime deposits. Difficulty swallowing food – the pigeon keeps its mouth open, tries to eat but cannot. Breathing problems – if the throat is blocked, the bird struggles to breathe and may make noise. Swollen thr