Home

>

Dog

>

Health & Wellbeing

>

Dog Skin Cancer

Dog Skin Cancer

Updated on February 03, 2023
Reviewer Profile Photo
Reviewed by Dr. Elyse Macartney
DVM

Types | Symptoms | Causes & Prevention | Diagnosis | Treatments

Dog getting an IV

Have you noticed a strange or new lump, bump or discoloration on your dog’s skin? There are many possible culprits, from allergies to skin tags, but it could also be dog skin cancer. As with all cancers, identifying skin cancer in dogs is crucial for the best prognosis. If you notice changes in your pet’s skin, see a veterinarian as soon as possible.  

Types of dog skin cancer

There are many different types of dog skin lesions and cancer, which can be either benign (not harmful) or malignant (harmful). Here are some of the most common types.  

Mast cell tumors  

Mast cell tumors are the most common malignant skin cancer in dogs and typically occur between the ages of 8 and 10. They grow from the mast cells, which are responsible for releasing histamines during allergic reactions, and look like lumps beneath the skin. They can grow anywhere on the body but are most common on the legs, chest and lower abdomen. They’re also more common in Pugs, Boxers, Boston Terriers and Rhodesian Ridgebacks.  

While they may look like a single tumor, mast cell tumors are surrounded by many smaller tumors, which can make them difficult to remove. That’s why they’re graded on a scale of one to three: Grade-one tumors are the easiest to remove surgically, while grade three tend to grow back and spread. The larger the tumor, the more difficult it will be to remove, so if you notice a strange lump on your dog, head to your veterinarian.  

Melanoma  

Melanomas are raised or flat spots or patches of dark-pigmented skin that grow from the melanocytes in the skin. They’re often benign, but when they are malignant, they tend to be very aggressive. Benign melanomas most frequently develop on the front legs and head, while malignant melanomas more commonly occur on the mouth, lips and nail beds. The malignant form of this dog skin cancer is most common in Schnauzers, Scottish Terriers and other dark-colored breeds.  

Malignant melanomas spread quickly and can even affect internal organs. There is often just one, but there can also be multiples, especially on at-risk breeds. Removal is typically effective. Malignant melanomas may require more aggressive dog skin cancer treatment.  

Squamous cell carcinoma 

Squamous cell carcinoma tumors vary in appearance from ulcerated patches to plaques, may be red, brown or black, and often appear on the lower abdomen where thin fur can let in ultraviolet radiation from the sun. They also occur on the head, lower legs and rear end. Squamous dog skin cancer is most common in dogs with white, thin or short hair, especially Beagles, Bull Terriers, Pit Bull Terriers, Standard Poodles and Dalmatians. 

Squamous cell carcinomas typically appear in older dogs and may start out as just a small bump. However, squamous dog skin cancer can progress quickly, spreading to the surrounding tissues and causing open lesions. It’s important to have it analyzed and removed immediately, even if it appears to be just a harmless bump.  

Dog skin cancer symptoms

The symptoms of dog skin cancer can vary widely depending on its type and how far it has progressed. Some of the most common dog skin cancer symptoms include: 

  • Lumps on the skin or underneath the skin
  • Skin that is bleeding or oozing pus
  • Skin discoloration
  • Thickened skin
  • Skin with an abnormal texture
  • Itchy or painful spots

As skin cancer in dogs progresses, it can invade other body systems or cause secondary symptoms. Dogs with mast cell tumors, for example, may experience stomach ulcers due to overactive histamines. In these cases, you may notice: 

  • Lethargy
  • Lack of appetite
  • Weakness

Because symptoms vary widely and skin cancer in dogs can be either benign or malignant, any unusual lumps, bumps or patches on your pup warrant a trip to your veterinarian.  

Dog skin cancer causes and prevention

You may think that all dog skin cancer is caused by the sun, but this isn’t the case. Only squamous cell carcinoma is linked to prolonged ultraviolet exposure.

Genetics play a role in the risk of cancer, which is why certain breeds are more likely to develop certain types of skin cancer. Purebred dogs, especially Boxers, Beagles, Bernese Mountain Dogs, Golden Retrievers and Rottweilers, are more likely to develop cancer in general, while Chihuahuas, French Bulldogs and Pomeranians are the lowest risk breeds. Overall, cancer is also more common in older dogs, which may be due to a weakened immune system, prolonged exposure to carcinogens or an increased chance of cell mutation.  

Our dogs are also exposed to the same environmental carcinogens as we are, including cigarette smoke, air pollution and pesticides. Dog nutrition may also play a role. While the exact causes aren’t always clear, you can help prevent skin cancer on dogs by using dog-formulated sunscreen, keeping your pet mostly indoors during the middle of the day, and using UV-blocking window screens. You should also limit their exposure to known carcinogens like smoke, pollution and pesticides.  

Diagnosing dog skin cancer

The first step in diagnosing dog skin lesions and cancer is to be a vigilant pet parent. While you give your pup belly rubs or groom them, check for new or strange-looking patches of skin. Because skin cancer on dogs can be hidden by the fur or appear on the underside of the body, it’s often hard to spot unless you’re looking for it.  

If you notice anything unusual, the next step is a visit to the veterinarian. They’ll perform a basic physical exam, including palpating the abdomen and looking at the mouth, nose and ears. They’ll look at the unusual patch of skin and carefully examine the rest of the body for any other bumps or patches.  

If skin cancer is suspected, your vet may be able to remove a small amount of cells with a needle and study them under a microscope. If that isn’t possible, they’ll need to do a biopsy, a quick surgical procedure to remove a small piece of the tumor and send it along to a pathologist. The pathologist will put together a report on the type of cancer, grade and characteristics.  

Certain types of skin cancer in dogs are known to spread, so additional diagnostics may be needed. Urinalysis, blood work, X-rays or ultrasound can help determine if the cancer is affecting the internal organs. Your veterinarian will put all this information together to create a treatment plan for your pup.  

Treatment for dog skin cancer

Your dog’s specific treatment plan will depend on their health, the type of cancer they have and how far it has progressed. But nearly every treatment plan for skin cancer in dogs involves surgery, radiation, chemotherapy or a combination of those. Palliative care is also an option.  

Surgery

Because skin cancers typically occur on the outside of the body, particularly in their early stages, they are usually good candidates for surgery. Surgery is the most common dog skin cancer treatment and is used for both malignant cancers and benign tumors that are unsightly, cause discomfort or interfere with a dog’s quality of life.  

Surgery for skin cancer is straightforward: The veterinarian will use surgical tools to remove as much of the cancer as possible with the goal of removing all cancerous cells. If the cancer is in the early stages, no other treatment may be needed. Even if surgery doesn’t remove all cancerous cells, however, it can often remove many of them, and then supplementary treatment can be used to kill the remaining cells. Partial removal, also called debulking, can also be used to help a pet be more comfortable. 

Radiation

Cancer cells divide extremely rapidly—that’s what causes the growths and discoloration often seen with dog skin lesions and cancer. Radiation uses a beam of energy to kill rapidly dividing cancer cells or damage them enough that they can no longer divide. It’s usually used in combination with chemotherapy and can also be used to “shrink” tumors so that they can be surgically removed.  

The exact treatment schedule will vary, but radiation is typically given in small doses over several weeks to maximize its effectiveness while minimizing possible side effects. Depending on where it’s targeted, side effects of radiation can include irritation, dry eye, nausea and loss of appetite. It can also damage healthy cells.  

Chemotherapy

Chemotherapy is the process of using drugs to kill cancer cells. It aims to halt and reverse the growth of the cancer with minimal harm to the healthy cells in the body. The drug, dosage and frequency will depend on your dog’s overall health, the type of cancer they have and how far it has progressed.  

Chemotherapy is often used in conjunction with radiation or surgery, and like those treatments, is most effective in cancer’s early stages. However, chemotherapy alone usually doesn’t completely eliminate skin cancer in dogs. Your veterinarian will work with you to evaluate the potential benefits against the side effects, which can include vomiting, lack of appetite and loss of white blood cells. 

Palliative care

Unfortunately, cancer can’t always be cured—and sometimes, the downsides to treatment outweigh the potential benefits. Palliative care is an approach that uses less-aggressive treatment methods and focuses on making your dog comfortable and improving their quality of life.  

Palliative care may involve dog vitamins and supplements as well as medications, especially for pain management. Managing pain also means providing a comfortable environment with minimal movement required. Your veterinarian can provide more information and help you develop a comfort care plan.  

Skin cancer in dogs can be hard to spot and often progresses quickly. If you notice any dog skin cancer symptoms, make an appointment with your veterinarian right away. Your neighborhood Petco Pet Care Center is here to help—we offer veterinary services, and we can also fill many dog prescriptions.  

image

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now
image

Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Filed Under

Sponsored