Pathological studies on neoplasms of dogs in South Africa

Abstract

In 1956 studies on neoplasms of dogs were commenced at the Liesbeek Clinic. De Kock (1957a) stressed the importance of these investigations, especially in respect of their comparative value to the study of neoplasms in man. Suitable forms were circulated amongst veterinarians and these were based on the observations published in a number of overseas journals. In such a survey of tumours in dogs in South Africa, special attention should be paid to geographical, breed, age, sex and site incidences, as well as to clinical data. The importance of careful autopsies was stressed for a proper reorientation of the site and nature of the tumour and the problem of metastasis, and the possible occurrence of multiple primary tumours. It entailed the proper selection of specimens and suitable smears for microscopical studies in order to arrive at a histological diagnosis. Large numbers of tumours in dogs have been investigated and described, e.g. by Feldman (1932), Jackson (1936), Innes (1943), Mulligan (1949), and others. Head (1959) and Cotchin (1959) have so far investigated close on 9,000 tumours in dogs. Jackson indicates that a full history of the subject, and a careful description of the specimen in situ are of great importance to the pathologist. Innes maintains that unless meticulous autopsies with histological examination are made on a long series of animals, many tumours may evade recognition or accurate diagnosis. The effective classification of neoplasms, according to Jackson, is one of the most subtle problems of pathology. There is a multiplication of nomenclature on the basis of variation of morphological appearance. He maintains that proliferative processes may be variously classed as nodular hyperplasia or as an adenoma in such organs as the liver, spleen, prostate, etc., and difficulties also arise in deciding whether one is dealing with a benign or a malignant tumour. Further comment on certain aspects of the pathology of tumours raised in the literature will be referred to when the results of the investigations at the Liesbeek Clinic are considered.