How to Care for a Dog with Breast Cancer (Mammary Gland Tumors)

Reviewed By Kyoko •  Updated: 03/22/21 •  7 min read
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There are many conditions that pet parents and their canine companions can get—one of these is breast cancer, which are called mammary gland tumors in our canine fur babies. It’s hard to think of your fur baby have the “c” word, we understand. Dealing with this major health issue is also scary for you as a pet parent. Understanding this, we’ve put together an article that will take a look at what mammary gland tumors are, symptoms to watch for, and treatment options, along with how to look after your fur baby if they have this type of cancer.

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Mammary Gland Tumors in Dogs

Mammary gland tumors in dogs is one of the most common type of cancer in female dogs. It’s most common in girl dogs who have not been spayed, between the ages of 2 to 10 years old. Though rare, male dogs and puppies can also develop this form of cancer. Breast cancer is caused by uncontrolled growth of abnormal mammary gland (breast) cells. Just as in humans, hormones are known to play a role in the formation of breast cancer in our canine companions. In fact, mammary gland cancer is not as common in female canines that have been spayed before their first heat cycle.

In addition, if a dog is treated with hormones for another medical condition, there is a possibility they could develop this form of cancer. Hormone treatments that can lead to canine breast cancer include estrogen and progesterone. Dogs that are obese also have a higher risk of developing mammary gland tumors. Genetics is also suspected of contributing to the development of canine mammary gland tumors. Some breeds have a greater tendency to this medical issue including:

If the cancer isn’t treated, it will metastasize (spread) to other mammary glands, the lymph nodes, the lung and other organs in the body. Dogs may develop one mammary gland tumor, or multiple mammary gland tumors.

In addition, dogs that have already had one tumor are at increased risk for developing one or more tumors in the future

Malignant or Benign Tumors

Mammary gland tumors come in two common types:

Dog Breast Cancer Symptoms

The symptoms of breast cancer in dogs may include:

Is mammary cancer in dogs painful? Yes, it can be, especially if the skin over the mammary gland has become ulcerated and/or infected. If you notice your fur baby is having any of these signs and symptoms, it’s best to take them to the vet as soon as possible. Early treatment can mean a better prognosis for your canine companion.

Signs that the cancer may have spread include:

These signs and symptoms generally indicate the cancer has spread; however, these can also be signs of other medical problems. So, if your pup is displaying these signs, be sure to get them to the vet as soon as possible.

Diagnosis of Mammary Gland Tumors in Dogs

The vet will first ask questions about your dog’s symptoms, such as when you first noticed any signs or symptoms, were there any other indications of a problem, etc. Try to be as accurate as possible when giving this information to the vet. It could well help with the diagnosis. Next, the vet will perform a physical exam of your dog, including the masses. The vet will also consult their records as to any treatments your canine companion has had, her last heat cycle, the medication she’s on and if she’s had puppies or not. They may then order some tests including x-rays and ultra sound, which can help the vet determine if the cancer has spread or is localized. However, these tests may not show microscopic cancer cells, which are too small to be seen via these methods.

Some vets will also order a fine needle biopsy and nearby lymph nodes. Other tests may include a urinalysis, complete blood count, and a blood chemistry profile. This last test will give the vet information on whether or not your fur baby is healthy enough to have surgery and anesthesia. If the vet suspects cancer, they may refer you and your canine companion to a vet oncologist. However, your vet may be the one in charge of treatment.

Treatment of Breast Cancer in Dogs

If your precious pup has been diagnosed with mammary gland cancer, then the next step will probably be surgery. The vet will remove the tumor, the tumor and a small area around it, or they may remove all of your dog’s mammary tissue, along with the lymph nodes. While this sounds drastic, it’s not as invasive as the procedure for us pet parents. In addition, if your fur baby has not been spayed, this may also be done at the same time.

Surgery is usually effective for removing the tumor(s), but it is possible the tumor or additional tumors could return. In dogs, chemotherapy and radiation are not usually effective; however, they may treatment options for tumors that have spread, are inoperable, or for tumors that have a high chance of spreading elsewhere in the body.

Dog Mammary Cancer Life Expectancy

The life expectancy for dogs with breast cancer varies depending on the size and type of tumor, and whether or not the tumor has spread. Dogs with small tumors generally have a longer life expectancy that canines with larger tumors. And dogs with breast cancer that hasn’t spread have a better prognosis.

If the cancer has spread to other body organs, this is a worse prognosis, with a shorter life expectancy

Dog Breast Cancer Surgery Cost

The cost of treating mammary gland cancer in dogs will vary depending on the type of treatments used and where you live. In general, this type of cancer treatment may cost anywhere from $1000 for a relatively easy surgery up to $15,000 if treatment includes chemotherapy and radiation.

Recovery After Breast Cancer for Dogs

After surgery, dogs will need a recovery period. This is usually shorter than it is for us. In fact, a dog may heal in just two weeks after this type of surgery! During this time, your fur baby will need a quiet place to rest, a calm environment and lots of love and attention. Make it a regular habit to check your fur baby’s mammary glands on a regular basis. Once a month is a good idea. Look for any of the early signs and symptoms that something could be wrong and call the vet immediately.

Cancer is a scary diagnosis no matter if it’s for one of our loved ones or for a beloved fur baby. However, with early detection and treatment, there’s a chance that your precious pup will go on to lead a normal, happy life span.  We wish all the best for you and your precious fur baby!

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Kyoko is from a family of 3 and moved to New York with her parents and siblings when she was 13. Kyoko is fond of spending a great amount of time with pets, specifically her beagle Luna and cat Missy. Her boyfriend often complains that she spends too much time giving attention to their animals. Kyoko has written dozens of articles concerning pets and is aiming at owning a pet shop one day!

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