EN
Mammary fibroepithelial hyperplasia (fibroadenoma) is a non-malignant lesion of the mammary gland, occurring in young female felines as a result of overproduction of progesterone or the use of gestagens. This disease is characterized by an increase in the size of several or all mammary glands which are enlarged and accompanied by pain, often with mastitis. In three cases of feline fibroepithelial mammary gland hyperplasia (two spontaneous and one after depo-gestagens treatment) antigestagen (alepristone) was used. The results obtained suggest that progesterone receptor blockers should be the first active drug treatment for cats with fibroadenomatosis because this encourages speedy remission of lesions and does not influence the cats’ fertility as was the case with previous therapy methods.