Canker is caused by a flagellate protozoan and is also known as trichomoniasis, roup or frounce. It is not transmittable to humans or other mammals, but can be caught by other birds that share the same water, eat seed dropped by an afflicted bird, or through direct beak-to-beak contact. The organism Trichomonas gallinae lives in the sinuses, mouth, throat, oesophagus and other organs. This disease occurs worldwide in warm climates or during warm weather.