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Types of Cancers in Dogs

Types of Cancers in Dogs

It can be daunting when you find a lump or bump on your dog. While many lumps are non-cancerous, there are several cancers in dogs that can cause tumors. Today, our Phoenix vets discuss types of tumors in dogs and what to do if you find one. 

Tumors in Dogs 

Tumors happen when a cell continues to multiply out of control instead of following the natural cycle. Just like humans, dogs can have tumors that are benign (non-cancerous) or malignant (cancerous). 

Benign Tumors 

In good news for pet owners, many of the tumors you may find on your pup are benign, which means they are not cancerous and will not spread or infect healthy tissues.

If your pet is diagnosed with a benign tumor, your vet will let you know if any further treatment is required, but often dogs can live a long and healthy life with a benign tumor. 

In some situations, a benign tumor may still need medical attention if it has a risk of growing too large and causing your dog pain or discomfort. 

Here are some common benign tumors found in dogs: 


Lipomas are benign fatty tumors that are typically found in the fatty layer just under a dog's skin, known as their subcutaneous fat.

These common tumors can sometimes get very large and may need to be removed if they are in a bad location. For example, a large lipoma located under a dog’s leg can cause issues with movement.

Occasionally this tumor is malignant and known as a liposarcoma, but this is much this common.

Commonly affected breeds: Weimaraners, Doberman Pinschers, German Pointers, Springer Spaniels, and Labrador Retrievers.


These benign tumors arise from histiocytes, a type of cell that fights infection, in the skin. They will frequently regress and resolve on their own within a few weeks. Sometimes they can become flat, ulcerated, or red across the top. They are sometimes colloquially known as 'button tumors'. 

Commonly affected breeds: Typically young (under 2 years of age) Labrador Retrievers, Boxers, Shar Peis, Bulldogs, American Pit Bull Terriers, Staffordshire Terriers, and Scottish Terriers. 


Papillomas, also called warts, are benign tumors caused by the canine papillomavirus. The virus is spread via contact between infected dogs and is common in dogs that spend a lot of time at dog parks, boarding facilities, or doggy daycare. Papillomas often occur on the lips, tongue, throat, or gums, although they may appear in other locations as well.

This tumor-causing virus can affect any breed of dog but cannot be spread from dog to human. 

Malignant (Cancerous) Tumours 

Malignant tumors spread and can cause damage to healthy tissues and make your dog quite sick if left untreated. Depending on the type, location, and size of a cancerous tumor, there are a variety of treatment options available. There are many types of tumors but here are the most common:

Mast Cell Tumours 

Mast cell tumors are malignant tumors that occur in the mast cells in a dog’s skin. Normal mast cells are a type of immune system cell that play a role in allergic reactions (such as bug bites). Mast cell tumors may look like a lot of different things, including a simple pimple or cyst. They can also mimic benign tumors such as lipomas. This is why it's always a good idea to err on the side of caution and get any new lumps or bumps on your pet checked out. 

Commonly affected breeds: Beagles, Boston Terriers, Boxers, Bulldogs, Bullmastiffs, Golden Retrievers, Labrador Retrievers, Pugs, and Weimaraners.


Lymphoma is a type of cancer that arises from white blood cells called lymphocytes. Normal lymphocytes are an important part of a dog's immune system.

Lymphoma often presents as large, firm lymph nodes that are typically found around the jaw, in front of the shoulder, or on the back of the knees. 

Commonly affected breeds: Golden Retrievers, Boxers, Bullmastiffs, Basset Hounds, Saint Bernards, and Scottish Terriers.


Osteosarcoma is a type of cancer that arises from bone cells. Osteosarcomas are often painful and can result in bone fractures, limb swelling, and lameness.

Commonly affected breeds: Boxers, Golden Retrievers, German Shepherds, Great Danes, Great Pyrenees, Greyhounds, Labrador Retrievers, and Rottweilers.


Melanoma is a type of malignant tumor that arises from pigment-carrying cells in the skin called melanocytes. Melanomas in dogs can often be pink or non-pigmented. They can also be flat rather than raised. 

In dogs, most melanomas occur in the mouth but they can also be found on the skin, in the eye, or on your pup's nail beds. 

Commonly affected breeds: Schnauzers and Scottish Terriers.

Treatment for Dogs with Tumours 

The treatment for your dog's tumor depends on whether or not it is cancerous or benign. Benign tumors often do not need treatment unless they are causing your pup discomfort or interfering with their general wellbeing. 

Cancerous tumors, on the other hand, can be treated with a variety of methods, and thanks to advancing veterinary technology, many dogs with cancerous tumors have a good prognosis. 

Your vet will recommend a course of treatment, that could range from surgery to chemotherapy, and work with you to ensure your pup is as comfortable as possible. 

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

Have you found a new lump or bump on your dog that is causing you concern? Contact our Phoenix emergency vets today to discuss your options for diagnosis and treatment.

New Patients Welcome

At Phoenix Veterinary Referral & Emergency Center, we are accepting new patients and referrals for our emergency and specialty services. Our team of experienced veterinarians and on-staff specialist are passionate about the health and well-being of pets in the Phoenix area. Contact us today to inquire about appointments or find out about the referral process.

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