Feline mammary tumours and dysplasias conclusions based on personal studies and some suggestions for future research.

Summary Feline mammary tumours and dysplasias were studied by various methods: morphological, electron-microscopical, immunological and virological. The most important conclusion was that cats with mammary tumours (benign and malignant tumours and lesions, the significance of which is not known so far) may be suitable animal models for the study of certain features of human mammary tumours; for instance, the study of the relationship between particular histological and biological characteristics of mammary carcinoma and the prognosis; the study of the question whether a virus (or viruses) does (do) or does (do) not play a role in the pathogenesis or growth of mammary tumours; the study of the possible presence of specific cellular and/or humoral immunity to mammary tumours and the study of the possible effects of progestogens on the mammary gland. As the study can not be regarded as a self-contained entity, it should be continued; this applies particularly to those parts of the study, that offer the best prospects for comparative investigations.