"Trichomoniasis (also known as trichomonoses) is an infectious disease caused by the microscopic parasite Trichomonas gallinae. It is a well documented illness in many bird species, primarily pigeons and doves (commonly known as canker) and raptors (commonly known as frounce), but also in passerine birds, particularly finches. The parasite inhabits the upper digestive tract, mainly the crop and esophagus, but it may also infect the liver, lungs, air sacs, internal lining of the body, pancreas and bones and sinuses of the skull. Trichomonosis was first documented in wild birds in Atlantic Canada in 2007, and it has been encountered regularly in the purple finch and American goldfinch populations in the region since that time. The reason for the emergence of trichomonosis in finches is uncertain, although there is some evidence that backyard bird feeding and watering might be involved in the transmission of the disease."