Pets get breast cancer too

As women worldwide take steps to prevent breast cancer so should pet owners.

Veterinary statistics show that as many as 1 in 4 unspayed female dogs will get breast cancer; in humans, that number is 1 in 29.

Most pet owners are unaware that dogs and cats get breast cancer (also known as mammary cancer) yet is also the second most common type of cancer affecting unspayed female cats.

“Sterilisation is critical in preventing mammary cancer,” says Dr Ingrid de Wet, veterinarian at Country Animal Clinic in Somerset West. “Dogs and cats that have not been spayed before the age of one are at a much higher risk of breast cancer.”

Spaying before the first heat reduces the risk of mammary cancer in cats by about 90%, while spaying before the age of one reduces the risk by 85%. If a dog is allowed to experience more than one heat cycle, the risk of tumours goes up to 1 in 4. “Sterilisation can also slow down the progression of mammary cancer if it has already occurred,” says Dr De Wet, “and it has other health benefits. It eliminates the risk of ovarian cancer and life-threatening infections of the uterus (pyometra).”

As with people, early detection of tumours is paramount in offering the best prognosis with treatment. The sooner the cancer is found, the more surgically removable a tumour is, the lesser the likelihood of spread to other tissues. “Generally treatment involves removal of the tumour; this may be removal of only one glad or removal of all or a few of the glands on the affected side. Lymph nodes may also need to be removed,” says Dr De Wet.

The tumours are then sent to a laboratory for analysis to determine the prognosis. “Some mammary tumours are benign but many are not which means that the cancer can quickly spread to other glands and organs. Chemotherapy and radiation are advised in some instances”.

Just as women inspect their breasts for lumps, pet owners are encouraged to do the same for their pets. “Owners should inspect the mammary glands at least once a month. This is best done by rolling the animal on its back and feeling up and down the length of the mammary glands from under the ‘armpits’ to inside the groin area,” says Dr De Wet. This is more difficult in cats as many don’t let owners feel their tummies but try to find a time when the cat is calm.

If a nodule, a firmness or unusual swelling is felt, consult a vet immediately.