Radical Mastectomy in Dogs

Diagnosis of mammary tumors in female dogs is fairly common. Often times these tumors are benign. About 50% of diagnosed tumors are found to be malignant and require surgical removal.  When a dog is diagnosed with mammary cancer, their surgical veterinarian or oncologist is often able to remove the dog’s mammary glands without the intrusive surgery humans require. If a radical mastectomy is necessary, all the mammary glands, as well as the surrounding lymph nodes, will be fully removed. 

About 70% of mammary cancer diagnosed in female dogs are in dogs who were not spayed before their third heat cycle.

Diagnosis starts at home with noticeable swollen mammary glands or a solid swollen mass. These masses could be as small as pea sized and will probably be hard to the touch and difficult to move under the skin. Some mammary masses could be larger, spreading across the abdomen. Because the diagnosis of tumor type is necessary, a biopsy will be performed by the veterinarian to determine if the tumors are malignant or benign. Depending on your veterinarian’s preference, a needle aspirate might be requested to diagnose and determine if the tumors are benign or malignant. Some veterinarians may perform the biopsy after surgery, depending on the aggressive behaviors of the tumors. A chest x-ray might also be needed to assist in determining the position and size of tumors. Moreover, a full panel Complete Blood Count (CBC) will help in diagnosing as well. A CBC will evaluate and measure the cells circulating in the dog’s blood.

Radical mastectomy involves the full removal of tumors and well as mammary tissue and the surrounding lymph nodes. Unlike the breast tissue in a human, mammary glands in dogs are just under the surface of their skin, not under the layers of muscles. For this surgery, the mammary tissue, as well as the skin covering the breast tissue and the four lymph nodes surrounding the mammaries, will all be removed. 

Though radical mastectomy is a surgery requiring anesthesia and recovery time, it is not as invasive as mastectomy surgeries in humans. Because anesthesia will be necessary, the dog will have to fast before surgery, usually overnight. It will be imperative the dog be kept calm and quiet for a few days post surgery. A cone or very loose fitting T-shirt will help in keeping the dog from irritating the incisions. Suture removal is usually 10 to 14 days after surgery. At this point, the dog should be able to return to regular activity. 

Some dogs, if not spayed already, will be spayed during surgery as well to assist in future tumor prevention.

Prognosis after surgery will depend on a few factors. The age of the dog will be significant, as well as the size and scope of the tumors. Tumors that have not spread to the lymph nodes have a high chance of being eliminated entirely and benign tumor removal has a high recovery rate. Tumors which have spread to lymph nodes have a lower success rate, however. Over half of the dogs treated with a radical mastectomy fully recover. 

With malignant tumors, early detection is a key factor to a successful radical mastectomy. 

Your veterinarian or oncologist might require follow-up appointments every three months for X-rays and blood work to ensure the tumors are not returning. 

There is no proven efficacy of chemotherapy or radiation in treating mammary tumors in dogs. Your veterinarian may recommend certain drugs before and after surgery. 

The dog will have to remain calm and relaxed post-surgery. Your veterinarian will prescribe medications based on your dog’s post-op condition. Your dog might be prescribed antibiotics and anti-inflammatory medications. Be sure to follow all instructions on the medications as well doctor’s instructions for aftercare. Your dog should avoid extensive exercise and rest as much as possible for the first several days and possibly up to two weeks. 

The veterinarian might recommend a cone to keep the dog from chewing and licking the sutures and surgical incisions. Be sure you return to your vet’s office if you see abnormal swelling and redness at the incision. 

After about 10 to 14 days, your veterinarian will remove any remaining sutures and clear the dog for normal play. It is imperative you continue to check the area for any returning tumors or growths. 

Costs related to a radical mastectomy will vary from start to finish. Your vet will start with blood test and x-rays to determine a diagnosis, which will contribute to overall costs. The low end in the range radical mastectomy surgery alone is about $500. If your dog requires a specialist, such as an oncologist, these costs can increase to $5,000 to $9,000.

Some veterinarians may offer chemotherapy or radiation as a less expensive option. However, there is little data proving the effectiveness of this treatment in dogs. 

The age of your dog will help determine the level of success a radical mastectomy might have; older dogs are at higher risk with a lower survival rate. Some dogs live years in remission. These dogs are usually young and healthy to begin with.

Early detection is key. If caught and treated early, mammary cancer is often curable. 

The type, size, and spread of the tumors will affect how well your dog does after surgery. 

Spaying your dog early, before their first heat cycle, offers the best method of prevention of mammary cancer and tumor growth. If a radical mastectomy is necessary and performed, consider spaying your dog during surgery to increase her odds of survival.

Prevention early on is vital for healthy mammary cell growth. Spaying small dogs before their first heat cycle and spaying large breed dogs at least before their third heat cycle is the best prevention you can give you dog for a healthy, long life. With a well-documented link between hormones and mammary tumors, spaying early gives your female dog the best chance to never have tumor growth. With each cycle the dog goes through, her chances of developing mammary tumors increases.

A healthy diet and daily exercise are factors in creating a long and healthy life for your dog. However, the number one path to not having mammary tumors is to spay early in life.