Cat 'Breast Cancer': Mammary Disease

Dr. Trisha Joyce, a veterinarian for New York City Veterinary Specialists, knows how lethal mammary disease -- cancer of the mammary glands -- can be in cats. The first case of mammary cancer she saw was with a cat that was brought in with a lump. “We removed the tumor and the cat was fine. Six months later, the couple and the cat were back. Another tumor had appeared. This one had ulcerated, and it was too late to treat it.”

Since that time, Joyce has counseled cat owners on how to prevent and detect mammary disease, and how to proceed once it’s been diagnosed. Below, she shares her advice on each of these.

Risk Factors

Mammary cancer is the third most common cancer among cats, and it is also one of the most preventable. “First and foremost, spay your cat,” says Joyce. Kittens spayed before they are six months old have a 91 percent reduction in their risk of developing the disease. Kittens spayed before they are one-year-old have an 86 percent risk reduction. In contrast, cats spayed before the age of two have only an 11 percent reduction, with no reduction of risk at all after age twp.

Mammary tumors are most commonly found in unspayed cats between 10 and 12 years old. The Daily Cat and The Dog Daily. She lives in New York City.