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Can Dogs Get Skin Cancer?

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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 nose, 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.

Protect Your Dog from the Sun

If your dog has short hair, either naturally due to breed or because of their 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 and is toxic to dogs. 

  • Test It Out
    Try out the product on your dog first by applying it to a small area of skin. Even if the sunscreen is made for dogs, your pup could have a reaction to it.
  • Apply as Needed
    Lather the sunscreen on areas of your dog’s body exposed to the sun. You don’t need to cover all of the very furry parts, or you’ll end up with one greasy dog!
  • Avoid Shaving
    A pet’s heavy coat acts as insulation and keeps your pet from overheating. If your pet has a thinner coat, you can try dressing them in sun-protective clothing. Choose sun protective clothing with lighter colors to help keep your dog cooler. Dark colors absorb and hold in heat from the sun.

Even if you’re very diligent about protecting your dog from the sun’s rays, they can still get canine 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 essential to get your dog a yearly check-up, so your veterinarian can look for signs of skin cancer.

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.

cocker spaniel mix dog walking on the beach

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 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.

Treatment for Dog Melanoma

The tumor may need to be removed surgically, which can be more complex with 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 effects for the dog.

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

Your veterinarian can help determine the best course of treatment for your dog. They 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 critical 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. 

To be safe, have your veterinarian check out any cut or sore that won’t heal on your dog.

Treatment for Squamous Cell Carcinoma in Dogs

There are several treatment options for squamous cell carcinoma (SCC) 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. SCC 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.

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 be required to diagnose this type of cancer and assess the situation.

Treatment for Mast Cell Tumors in Dogs

Treatment for a mast cell tumor in dogs is similar to treatment for squamous cell carcinoma. Typically, surgery will be needed to remove the tumor. After that, the dog may require 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. Learn more about what’s covered.

vizsla puppy taking a nap in a sun ray

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.

The information presented in this article is for educational and informational purposes only and does not constitute or substitute for the advice of your veterinarian.

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