THE USE OF DOGS FOR STUDIES OF TOXICITY OF CONTRACEPTIVE HORMONES

Abstract

ABSTRACT Responses to endogenous and exogenous sex steroids in the dog are characteristic for that species, differing in many important aspects from other laboratory animals and man. Long-term administration to dogs of progesterone and synthetic compounds structurally related to this natural gestagen has resulted in precocious development of mammary gland tumours and other changes suggesting stimulation of anterior pituitary activity. Progestogens structurally related to testosterone have not induced similar effects. Results obtained to date indicate a lack of relevance of data obtained in the dog to the prediction of clinical potential of sex steroids for mammary gland carcinogenesis.