THE USE OF DOGS FOR STUDIES OF TOXICITY OF CONTRACEPTIVE HORMONES

The response of the female dog to endogenous and exogenous sex steroids is unique to the species differing in many aspects from other experimental species and man. Long-term administration to dogs of progesterone and structurally related synthetic compounds has resulted in precocious development of mammary gland tumors and other changes suggesting stimulation of anterior pituitary activity. Progestogens structurally related to testosterone have not induced similar effects. The specifically unique characteristics of canine disposition in sex steroid experiments are discussed and it is concluded that there is a lack of relevant data obtained to predict the clinical potential of sex steroids for carcinogenesis of the mammary gland.(AUTHORS MODIFIED)