October is Breast Cancer Awareness Month, but chances are dog owners have no idea that their dogs can actually get breast cancer. The bad news is that breast (mammary) cancer in dogs is common; the good news is that the disease can be treated successfully if caught early.
According to veterinarian Dr. Race Foster, the most common type of tumor in female dogs is the mammary tumor—especially in (unspayed) dogs between the ages of five to 10 years-old. There are male dogs that do develop breast cancer and, sadly, their prognosis is not good because this type of breast cancer is very aggressive.
Signs of Breast Cancer in Dogs
Similar to human breast cancer, mammary tumors in dogs can range in size. Breast tumors in dogs often grow quickly with an irregular shape. These malignant tumors can also cause bleeding and ulceration. However, if your dog’s tumor does not exhibit these signs, that does not mean your dog is free from breast cancer; small tumors that have been present for a while can suddenly grow aggressively as well. As with most other types of cancer, once malignant tumors in dogs start to grow, the cancerous cells can spread to other parts of the body.
If you find a lump on your dog, do not wait to go to the veterinarian. It is always best to play it safe and have your dog examined by a licensed veterinarian who will perform a biopsy. Half of all mammary tumors in dogs are benign, but do you really want to play guessing games when it comes to your dog’s health?
Treatment of Canine Breast Cancer
Treatment of a malignant tumor usually involves surgery. Similar to breast cancer in humans, dogs will either have just the tumor removed or the entire mammary tissue along with lymph nodes. Dogs’ mammary glands are different than humans in that they are outside of the muscle, so the surgery is not as radical. Dr. Race Foster suggests that unlike humans, chemotherapy and radiation in dogs are not successful.
Canine Breast Cancer Prevention
The best way to prevent breast cancer in female dogs is to spay them before they go into heat for the first time—just another benefit of spaying. By doing this, dog owners can practically eliminate the chances of their dog developing mammary cancer.