Mammary cancer

A cat has four pairs of mammary glands along the belly. Tumors of these glands are the third most common cancer in cats, after lymphoma and skin tumors. Most are malignant, which means they can invade nearby tissue and spread to the lymph nodes and lungs. They are most often found in unspayed females around ten to twelve years old, and Siamese cats appear to be at higher risk.

The main sign is one or more firm lumps under the skin of the belly or chest. They may be small and slow to grow, or they may ulcerate and bleed. A cat may lick the area. Because cats are good at hiding discomfort, a lump may be the only warning. Run your hands along your cat's belly now and then, and see a vet about any lump, however small, since early treatment gives better results.

A vet confirms the diagnosis from a tissue sample, checks for spread with chest X-rays and blood tests, and usually advises surgery to remove the affected glands, sometimes followed by chemotherapy. Hormones play a part: cats that are spayed young, ideally before their first heat, have a much lower risk. Ask your vet about the right age for the surgery, and about checking the glands at each wellness exam.