A survey on neoplasia in domestic species over a 40-year period from 1935 to 1974 in the Republic of South Africa. VI. Tumours occurring in dogs.

A survey was carried out on all canine neoplasms recorded in the registration files of the Section of Pathology of the Veterinary Research Institute at Onderstepoort over a 40-year period from 1935 to 1974. The neoplasms were divided and tabulated into 14 groups according to body systems or tissue types. A total of 3 388 neoplasms were recorded. The 5 most frequently affected body systems were the mesenchymal tissues (33,7%) the skin and adnexa (20,8%) the female genital tract (10,2%), the lymphohaemopoietic tissues (8,9%) and the male genital tract (5,8%). Mastocytomas, the most frequently encountered type of tumour, accounted for 12,7% of all the neoplasms, followed by lymphosarcomas, melanomas, squamous cell carcinomas, basal cell tumours, haemangiosarcomas and histiocytomas. A variety of mesenchymal tumours were encountered, the most common types being mastocytomas and histiocytomas as well as tumours of vascular, fibrous and adipose tissue origin. The principal cutaneous tumours included basal cell tumours, squamous cell carcinomas, perianal gland tumours and melanomas. Eighty per cent of the neoplasms of the female genital tract were mammary tumours, 50% of which were mixed mammary tumours, whilst the principal neoplasms of the male genital tract involved the testes, of which Sertoli cell tumours were the commonest type. The majority of the digestive tract neoplasms occurred in the oral cavity, the most frequently recorded types being inflammatory epulides and melanomas. Osteosarcomas, neurofibromas and thyroid carcinomas were, respectively, the most frequently encountered neoplasms of the skeletal, nervous and endocrine systems. Pulmonary adenocarcinomas, melanomas and cholangiocarcinomas were the commonest tumours of the lung, eye and liver.