Can Dogs Get Skin Cancer?

You might think that your dog’s furry coat protects them from skin cancer, but this isn’t truly the case. Even with all that hair, they can still be exposed to harmful UV rays, particularly on areas of their body with little to no hair, like the noses, tummy, and paw pads.

Breeds with light colored or thin coats, such as Chihuahuas or Greyhounds, can be more at risk for damage from the sun. There are also some forms of dog skin cancer that aren’t caused by time spent in the sun.

Protecting your dog from skin cancer and the sun

Protect Your Dog from the Sun

If your dog has short hair, either naturally due to breed or because of his or her haircut, you should use sunscreen to protect against harmful rays. Look for sunscreens designed specifically for dogs or ask your veterinarian for a suggestion. Be sure to avoid products with zinc oxide. It’s commonly found in sunscreen, but toxic to dogs.

Even if you’re very diligent about protecting your dog from the sun’s rays, he or she can still get skin cancer. The good news is that it can often be treated successfully, even more so if it’s caught early. This is one of the reasons it’s important to get your dog a yearly check up, so your veterinarian can look for signs of skin cancer.

Did you know annual exams can be covered with an ASPCA Pet Health plan that includes a wellness option? Start a quote to see what’s available for your dog.

In addition, you should make an effort to look over your dog’s coat and skin at home on a regular basis. You can look for dark spots or irritated patches of skin as well as lumps or bumps. A careful home skin check can also help you detect other issues, such as fleas, ticks, and common skin conditions.

Don’t jump the gun and panic if you find anything, since these issues don’t always mean cancer. However, you should contact your veterinarian who can figure out if there is something worrisome.

It’s important to get your dog a yearly check up, so your veterinarian can look for signs of skin cancer.

Types of Dog Skin Cancer

While many of the lumps and bumps that appear on our four-legged friends as they age are benign, there are several different types of skin cancer and malignant tumors that can show up in dogs. These include melanoma, squamous cell carcinoma, and mast cell tumors.

Melanoma in Dogs

Sun exposure is the typical cause of melanoma in humans. However, the link between UV rays and melanoma in dogs is unclear. It can occur in areas that are not in the sun, such as a tumor in the mouth or on the toes.

These “cancer bumps” can cause swelling and redness around the area. With oral melanomas, you may also notice an increase in salivation and loose teeth. Melanoma in the toes can have additional symptoms including toenail loss and limping.

While oral melanomas are often black or pink, melanoma masses in the toes are typically black. Your veterinarian can use a fine needle to extract cells from the tumor for testing. If this procedure is inconclusive, a biopsy may be required.

happy dog rolling on ground

Treatment for Dog Melanoma

The tumor may need to be removed surgically, which can be more complex with an oral melanoma. The surgeon needs to remove all of the cancerous tumor without damaging the jawbone. Damage to the jawbone could affect the dog’s ability to eat, drink, chew, and play.

With a toe melanoma, the surgeon may simply remove the entire toe without any adverse affects for the dog.

Other treatments for melanoma can include radiation, chemotherapy, and additional medications. For instance, there is a new vaccine that stimulates the immune system, so it can better fight off the melanoma.

Your veterinarian can help determine the best course of treatment for your dog. He or she will consider factors such as your dog’s overall health, breed, location and size of the tumor, and whether or not the cancer has metastasized.

Unfortunately, about 50% of melanomas in the paw pads and nail beds spread to other parts of the body, according to the National Canine Cancer Foundation. Oral melanomas can also spread rapidly to areas including the lymph nodes and lungs. This makes early detection even more important to the chances of survival for your dog.

Squamous Cell Carcinoma in Dogs

Squamous cell carcinoma is a type of cancer that originates in the outer layer of a dog’s skin. This layer is called the squamous epithelium, and it covers most of the body and lines some of its inner cavities.

Overexposure to UV rays can result in squamous cell carcinoma. It can look like a raised bump or white skin mass. The mass may begin to die off in the center causing it to resemble an open sore that occasionally bleeds.

Have your veterinarian check out any cut or sore that won’t heal on your dog, just to be safe.

Dogue de Bordeaux playing outside

Treatment for Squamous Cell Carcinoma in Dogs

There are a number of treatment options for squamous cell carcinoma in dogs. For instance, if this type of cancer presents as a small mass, your veterinarian may be able to use cryosurgery, which is a freezing technique, to remove it. Bigger tumors may need to be surgically removed. Skin grafts may be necessary if a large area of skin needs to be taken off during the surgery.

Surgery may be followed up with radiation and chemotherapy to help ensure the eradication of all the cancerous cells. If surgery is not an option, your veterinary may recommend radiation, chemotherapy, or a combination of both to treat your dog.

As with melanoma in dogs, early detection is key to boosting your dog’s chances of survival. It is typically less aggressive than melanoma, but can destroy much of the tissue in the area.

You can help prevent squamous cell carcinoma by limiting the time your dog spends in the direct sun, applying sunscreen, and dressing your dog in sun protective clothing as we mentioned earlier.

Mast Cell Tumor in Dogs

Mast cell tumors are the most common cutaneous tumor found in dogs as reported by the National Canine Cancer Foundation. But, it’s not known what exactly causes this type of cancer. It has been linked to skin irritants, inflammation, and genetic factors.

What Are Mast Cells?

Mast cells are found in connective tissue, particularly near the skin, nose, lungs, and mouth. They help fight off parasitic infestations, repair tissue, and form new blood vessels. They also take part in allergic reactions by releasing various chemicals that affect inflammation and other immune responses.

Why these cells become cancerous is still a mystery, but they can form masses that range from just a millimeter to three or more centimeters big. They typically redden when you touch them and may appear larger and smaller at different times due to swelling. They can also make your dog feel itchy causing a lot of scratching or chewing in the area.

As with melanoma in dogs, your veterinarian may use a needle to extract cells for testing. A biopsy, as well as other testing, may also be required to diagnose this type of cancer and assess the situation.

Lulu’s multiple surgeries to remove mast cell tumors were worth it in the end

Treatment for Mast Cell Tumors in Dogs

Treatment for a mast cell tumor in dogs is similar to treatment for that of squamous cell carcinoma. Typically, surgery will be needed to remove the tumor. After that, the dog may need radiation, chemotherapy, or a combination of both to make sure any remaining cancer cells are destroyed.

One of our team members at ASPCA Pet Health Insurance had an experience with mast cell tumors that she shared with us:

“I noticed a bump under Lulu’s armpit one day while giving her a belly rub. I didn’t think much of it until she began relentlessly scratching at the spot. I checked it again, and the bump appeared to have grown larger. So, I took her to the veterinarian, and they recommended aspirating the bump to see if it was malignant. When the tests came back positive, we scheduled surgery immediately. Thankfully, the veterinarian and her team were able to remove it all.

Because of this initial experience, I was ready the next time when less than a year later, Lulu began scratching a spot on her tummy. The second bump also came back malignant, and we scheduled another surgery. While the cumbersome recovery process included her wearing a cone, a t-shirt, and a pair of shorts so that neither set of paws could reach her long line of stitches, it was all worth it in the end.”

As you can see from all of this, cancer can be a complex and costly health issue to treat, and dogs of any age or breed are susceptible. You can get help managing the costs of treating cancer, including diagnosis, medications, surgery, hospitalization, and even radiation and chemotherapy with an ASPCA Pet Health Insurance plan. Get a free quote for your dog now.

white dog playing outside

Benign Bumps

Not all lumps and bumps you may find on your dog are cancer. Dogs can also have bumpy issues, such as fatty deposits, skin tags, and warts.

Fatty Deposits

Fatty deposits, also called lipomas, feel soft and move around under the skin fairly easily. They typically don’t make dogs uncomfortable unless they are in an area that inhibits movement. Quite often dogs will develop multiple fatty deposits, which usually form on the belly or torso. Fatty deposits don’t usually need removal unless they’re causing a problem for the dog.

Skin Tags

Skin tags, which are soft pieces of flesh, form on dogs from the excessive growth of skin cells, much like they do in humans. They can appear anywhere on a dog’s body, and typically don’t need to be removed unless they become infected or irritated.


Dog warts may not be pleasing to look at or think about, but they aren’t problematic. Like warts on people, they’re benign lumps that form as a result of a virus called papillomavirus. They don’t require medical attention unless they’re located somewhere that causes an issue, such as near the eye or under the collar where it may get rubbed and irritated.

Curious to learn what else might be going on with your dog’s skin? Check out this article on common dog skin issues to see what all that scratching could be about.


Find Articles