Dog Skin Cancer Breakdown: Types, Causes and Treatment Plans

Published June 7, 2022
dog getting an exam for skin cancer at the veterinarian office

You may not think your dog could get skin cancer because their bodies are protected by their fur, but skin cancer can occur even without significant sun exposure. Fortunately, when caught early and treated, it's not usually fatal. Understanding the signs of skin cancer in dogs is critical to your dog's health.

Types of Skin Cancer

There are three types of skin cancer that are most common in dogs. Each type of cancer affects your dog differently and may have a slightly different treatment path. If you find an unusual or suspicious marking on your dog, and you suspect it may be skin cancer, take your dog to the veterinarian right away.

Mast Cell Tumors

Mast cell tumors affect mast cells in the immune system and are the most common type of skin cancer in dogs. Scientists are unsure of the cause of mast cell tumors, also known as MCTs, but inflammation of the skin is thought to be a contributing factor. Genetics and hormone regulation are also thought to be connected to mast cell tumor growth.

Malignant Melanoma

Malignant melanoma is a type of cancer that affects cells known as melanocytes. They often occur in the mouth or mucus membranes but can be found on other parts of the body. Oral melanomas typically present as pink or black areas, whereas toes are generally black in color. This type of skin cancer is known for fast growth and increased levels of metastasis (cancer spread). The lungs and the liver are usually the first organs affected by the growth of this type of cancer.

Squamous Cell Carcinoma

Squamous cell carcinoma is the type of cancer caused by increased sun exposure. Squamous cell carcinoma is a kind of cancer that develops from squamous cells, which means that tumors can develop everywhere that these cells are present. There are several places where this can occur, including the nail bed and paw pads, abdomen, back, ears, and nose. When this cancer spreads, it often metastasizes to the lymph nodes and destroys the tissue surrounding the tumor.

Breeds Affected by Skin Cancer

All breeds can develop skin cancer, but there are several dog breeds that are most prone to skin cancer development. Breeds commonly affected by mast cell tumors include Boston Terriers, Labrador Retrievers, Rhodesian Ridgebacks, Beagles, Schnauzers, Boxers, and Pugs between the ages of 8 and 10. Those commonly affected by malignant melanoma include the Vizla, Miniature Schnauzer, Doberman Pinscher, Chesapeake Bay Retriever, and Airedale Terrier. Dogs prone to squamous cell carcinoma include Basset Hounds, Beagles, Bull Terriers, Collies, Dalmatians, Keeshonds, Standard Schnauzers, and Whippets that are between 5 and 10.


Of course, you can't prevent skin cancer in your dog, but you can take the steps necessary to reduce the risk. Visit your veterinarian, at minimum, for your pet's annual wellness visit. You should also limit their exposure to the sun. Don't keep them indoors completely, but on days the sun is shining down intensely, be certain to go in and out of the shade.

Every few weeks, especially during petting and grooming, check for areas on your dog's skin that are abnormal. If something seems off, call your veterinarian for a check-up. You can't prevent all cancers, but you can be proactive about your pet's health.


If your veterinarian suspects your dog has skin cancer, they will perform a fine needle aspiration to test the cells in the suspicious area. Those cells will be sent to a lab for further examination to determine if there are any cancer cells present. If the lab confirms skin cancer, your veterinarian may recommend additional testing to determine the severity of the cancer. This will aid in developing a treatment plan and providing you with a prognosis.


The treatment option for your dog's skin cancer will depend on a variety of criteria, including the tumor's type, grade, and location. Age and general health will also play a part in developing a treatment plan. For mast cell tumors, surgery is generally recommended in addition to radiation in some cases. If the cancer is in advanced stages, chemotherapy and steroids, like prednisone, may be involved in treatment, as well.

Malignant melanomas also often require surgery. However, if the melanoma has dirty margins and cannot be removed completely, radiation should follow surgical intervention. When surgery and radiation are combined, 70 percent of dogs have been shown to go into remission.

Unlike the other two common skin cancer types, squamous cell carcinomas are often removed with surgery without the need for radiation. If the tumor does occur in a location where surgery cannot be performed, piroxicam and photodynamic therapy may be implemented.

Detect Cancer Early

The discovery of skin cancer in its early stages greatly improves the success rates of treatment. Check your dog for lumps, bumps, or anomalies during petting and grooming. If you notice anything suspicious, contact your veterinarian. It's better to be safe than sorry, especially when it comes to cancer.

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Dog Skin Cancer Breakdown: Types, Causes and Treatment Plans