[The significance of ovariectomy and progestagens in the development of mammary carcinoma in cats].

Mammary carcinoma in the cat has a poor prognosis. Because of metastasis and local malignity, these tumours are of relevance not only to veterinary practice but also to comparative research as a model to study possible therapies and the aetiology and pathogenesis of the disease. Little is known about the development of mammary tumours in humans and companion animals. A case-control study was carried out to learn more about the role of endogenous and exogenous sex hormones. In the cat, ovariectomy (RR 0.36) had a clear protective effect against the development of mammary carcinoma, whereas regular administration of progestogens clearly increased the risk of carcinoma development (RR 2.81). Our results show that with regard to the evidence of mammary carcinoma, oestrus prevention by ovariectomy is to preferred to the administration of progestogens.