Beak neoplasia in avian species: description of nine cases.

Beak neoplasia is a rare condition in avian species and is most often reported within the order Psittaciformes. Through a multi-institutional retrospective study, we describe nine cases of beak neoplasia from six species belonging to the orders Galliformes (Gallus gallus domesticus and Syrmaticus reevesii), Psittaciformes (Amazona sp and Ara sp), Anseriformes (Anas platyrhynchos domesticus) and Columbiformes (Columbina livia domestica). The sex distribution was four females, four males and one not specified. The average age at the time of diagnosis was 11.8 years (range 2-38 years; standard deviation ± 12.8 years). The most commonly reported tumour was squamous cell carcinoma, followed by melanoma; metastases were documented in both neoplasms. Other diagnosed neoplasms included undifferentiated carcinoma, lipoma and fibrosarcoma. Most neoplasms were located at the maxillary rhamphotheca (66 %; 6/9). Clinical signs included chronic weight loss, anorexia, hyporexia, inappetence, dysphagia, extensive ulceration of the beak keratin, secondary bacterial infection, halitosis, crop impaction and dyspnoea. The progression of neoplasms affecting the beak varied from 3 weeks to several years, leading to euthanasia in 55 % (5/9) of the cases.