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Mouth Cancer in Dogs

Although mouth cancer (mouth cancer) can be seen in dogs of any age, the most common age for a dog to be diagnosed with mouth cancer is 11 years. Here, our Pflugerville vets explain some symptoms of mouth cancer in dogs, and the available treatments for this disease.

What is mouth cancer?

Like a person's, your dog's mouth is made up of a number of different types of cells such as skin cells, fibrous cells, and bone cells. When cancer is present these cells change and begin to divide without control forming tumors (groups of abnormal cells that form lumps or growths) and invading nearby tissues.

Some forms of cancer grow slowly and are less likely to spread to other areas in the body, whereas other cancer cells (malignant or metastatic tumors) are more aggressive and can quickly begin to spread throughout your pet's body.

In dogs, the most common types of mouth cancer are are melanoma, squamous cell carcinoma and fibrosarcoma.

What causes mouth cancer in dogs?

In most cases it's not possible to determine the cause. However, a variety of genetic and environmental risk factors are typically at the root of mouth cancers in dogs. Breeds with a somewhat elevated risk of developing the disease seem to include Weimaraners, German shepherds, boxers, chows, and miniature poodles. 

What does cancer look like in a dog's mouth?

The average age of dogs diagnosed with mouth cancer is 11 years, although mouth cancer can be seen in dogs of any age. Which is why it's important know the signs of this disease and act quickly if your dog is showing symptoms of mouth cancer.

If your dog has mouth tumors, they may appear as swellings or lumps on the gums around the teeth, or on the roof of their mouth, although they can appear anywhere in the dog's mouth. These tumors will often break open and bleed which can lead to infection. 

Depending on the size, type and location of your dog's tumor, as well as the cancer's propensity to spread, mouth cancer tumors in dogs can be darker in color than the surrounding tissue (pigmented) or non-pigmented, they could also appear as smooth lumps or be more cauliflower-like in appearance.

You can search 'pictures of mouth cancer in dogs' or 'tumors in dog's mouth' or something similar into your favorite search engine for a general idea of what mouth cancer might look like in dogs.

How common is mouth cancer in dogs?

Mouth cancer in dogs is relatively uncommon, with some suggesting it only accounts for 6% of all canine cancers. However, it is important for pet owners to be aware of the signs and symptoms in order to catch it early for the best chance of successful treatment.

What are the most common symptoms of mouth cancer in dogs?

In dog's, the most common signs of mouth cancer include: bleeding from the mouth, bad breath, excessive drooling, trouble chewing, obvious signs of mouth pain, loose teeth, visible lump or mass inside of the mouth, swollen areas of the face, reluctance to eat and weight loss.

Is mouth cancer painful for dogs?

Mouth cancer in dogs can be painful, especially as the tumor grows and affects surrounding tissues. Signs of pain may include difficulty eating, drooling, and pawing at the mouth.

What are the stages of mouth cancer in dogs?

Mouth cancer in dogs ranges from Stage I to Stage IV:

Stage I: Tumor less than 2cm in diameter

Stage II: Tumor 2 to 4cm in diameter

Stage III: Tumor greater than 4cm in diameter and spreads to nearby lymph nodes on the same side of the body, or involves the bones.

Stage IV: Any tumor diameter and/or spreads to nearby lymph node and/or spreads to other parts of the body.

What is the treatment for mouth cancer in dogs?

Surgery tends to be the most successful treatment of mouth cancer in dogs. If the cancer is diagnosed early and the tumor is easy for the vet to access, surgery may even be curative.

For other dogs surgery may need to include the removal of a large portion of the jaw  in order to try and eliminate all or most of the cancer cells. 

While chemotherapy isn't generally considered effective as a treatment for mouth cancer in dogs, your vet may recommend radiation therapy or immunotherapy following surgery, to help kill cancer cells and allow your pet to recover.

Radiation can also be used in place of surgery if the tumor is too difficult to reach, or too advanced, to be removed by your veterinary oncologist, or can be used to supplement surgical treatment. Radiation for mouth cancer in dogs can cause redness, inflammation or ulceration of the mouth in some cases, but these symptoms typically clear up about a week after the radiation is administered.

What is the life expectancy for dogs with mouth cancer?

Early diagnosis and treatment are the key to good outcomes. If a tumor is detected early, depending on the type of cancer and the location, there is a possibility that the tumor could be surgically removed, boosting the survival rate of dogs with mouth cancer by about 5 years or more.

That said, if you're dog's mouth cancer isn't detected until the later stages, there is a good chance that the cancer will have already spread (metastasized) to other parts of the body. Sadly, dogs who are diagnosed in later stages may only live for another 6 months to year.

Left untreated, the prognosis for dogs with mouth cancer is very poor with an average survival time of 65 days.

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.

Contact Pfennig Lane Animal Hospital in Pflugerville for more information about oncological veterinary care, and to book an appointment, if your dogs has been diagnosed with mouth cancer. 

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Pfennig Lane Animal Hospital is accepting new patients! Our experienced vets are passionate about the health of Pflugerville companion animals. Get in touch today to book your pet's first appointment.

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