ABSTRACT
Advances in the prevention, diagnosis and treatment of infectious diseases, malnutrition, and other non-infectious diseases of birds have meant longer and healthier lives for companion birds. Most oncogenes require an additional step, such as mutations in another gene or environmental factors such as carcinogens, viral infections or dietary influences, to cause cancer. Radiation therapy uses an external beam of radiation to destroy the proliferative capacity of the tumour without irreparable damage to surrounding normal tissues. Tumours can be classified by the cell types within the tumour: carcinomas: malignancies of the epithelial cells; sarcomas: malignancies of mesenchymal cells; and discrete or round cell neoplasms: the only common neoplasm of this type is lymphoid neoplasia. Many neoplasms are discrete masses easily detected on physical examination. Anaemia is often present with chronic neoplasia. Radiology, ultrasound, computed tomography and magnetic resonance imaging are all useful adjuncts in the diagnosis of neoplastic disease.
