Yes, even animals get breast cancer.
By Dr. Amanda Newman, D.V.M. Benbow Veterinary Services
October is Breast Cancer Awareness Month, and, as humans, we know how serious the disease is. About 1 in 8 women in the U.S. will develop invasive breast cancer, and in 2018 about 2,550 new cases of invasive breast cancer are expected to be diagnosed in men in the U.S. Unfortunately, the majority of us know someone who has been affected by the disease, but we also know there have been great strides in progress to treat disease thanks to funding that supports research.
What most people are not aware of is that breast (mammary) cancer can also occur in dogs and cats, frequently in those that are not spayed. While the direct cause is still being studied, research has shown that some breeds are genetically predisposed to cancer in the mammary glands.
According to the American College of Veterinary Surgeons, “More than a quarter of unspayed female dogs will develop a mammary tumor during their lifetime. The risk is much lower for spayed female dogs, male dogs, and cats of either gender. In female dogs, 50% of mammary tumors are benign (not cancerous) and 50% are malignant (cancerous). However, few of the malignant mammary tumors are fatal. In contrast, over 85% of mammary tumors in cats are malignant and most of these have an aggressive biologic behavior (i.e., mammary tumors in cats tend to be locally invasive and spread elsewhere in the body).”
Dr. Cynthia Benbow recently discussed breast cancer in animals on her weekly segment, Ask The Vet.
If you or you and your veterinarian find a mass the next step would be to have it surgically removed and sent for a biopsy. If your dog or cat is not spayed your veterinarian will also spay her when removing the mass to reduce the risk of recurrence or future tumors. Depending on the results of the biopsy, you and your veterinarian would put together the best treatment plan for your pet. Treatment may simply involve the actual surgery of removing the mass(es) and spaying her, or it may include a more aggressive approach with chemotherapy, radiation and anti-estrogen therapy, in which case a veterinary oncologist may be consulted as well.
Once the mass is removed and initial treatment has been administered, a wellness and management plan that is diligently adhered to will help keep your fur baby on track in preventing the disease from coming back. An important part of the plan includes follow up exams every three months within the first 12 months following surgery, and every 6 months thereafter.
Just remember, the key to prevention is spaying your dog or cat before their first heat cycle (usually 6 months of age). As mentioned earlier, that would make the likelihood of them developing mammary tumors almost nonexistent. If for some reason your pet is not spayed, make sure to know your pet's body and have their mammary glands checked often! Your pet counts on you to make sure they get the best care possible, so they can be with you for the long run.