Feline mammary hyperplasia is an unusual but benign condition that can be confused with mammary cancer in cats. This condition tends to occur in young cats, even kittens. Literally overnight, the cat’s mammary glands can become very swollen. The condition is is caused by exposure to the hormone progesterone, which may be produced naturally during the cat’s reproductive cycle or may be given to treat certain diseases. The glands can ulcerate from the drastic swelling and are often painful.
Spaying can be curative, though if the glands are very swollen, spay surgery can be complicated. In some cases, the swollen, ulcerated glands must be surgically removed. The drug aglepristone is very effective at reducing the gland size, but is not currently available in North America.
