Observations on naturally occurring neoplasms in birds in the state of Victoria, Australia.

Forty-five types of naturally occurring neoplasms (383 cases) were identified in 69 avian species (excluding domestic fowl), belonging to 25 Families from 13 Orders. The most prevalent tumours were lymphomas (63 cases in 25 species), fibromas and fibrosarcomas (62 cases in 15 species), and lipomas and liposarcomas (56 cases in 16 species). There were mesenchymal tumours of the foot-pad in 13 Anseriformes, and a variety of tumours involving the reproductive tract of many species. Brief descriptions of the different neoplasms are given.