Dog Oral Cancer

Dog oral cancer can be a very aggressive form of the disease. There are several growths that can be found in a dog's mouth: some of these are benign, some are not.

Benign Oral Tumors

A benign tumor is one that has not metastasized. The borders of the growth are contained to one area, which is usually the periodontal ligament. Benign tumors do not grow into a dog's bone or tissue, and can be surgically removed.

Malignant Oral Tumors

A malignant tumor is one of the most common oral tumors a dog can acquire. There are three types:

  • Squamous cell carcinomas
  • Fibrocarcinomas
  • Malignant melanomas

Squamous Cell Carcinomas

These are typically located in one area of a dog's mouth and will metastasize later than other cancers might. This type of oral cancer usually affects the bone in a dog's mouth the most. Squamous cell carcinomas usually affect the front of a dog's mouth.


A fibrocarcinoma is a type of cancer that does not spread. Usually appearing in older male dogs, this malignancy often looks like red growths inside the mouth. Fibrocarcinomas are known to reappear after surgical removal was performed.

Malignant Melanomas

These are the most common form of cancerous tumors a dog can have in his mouth. The cancer can affect just one area of the mouth, or it can spread. The melanoma usually looks like dark bumps in the lower area of the gums. This form of cancer can also be in a dog's jaw bone. Malignant melanomas typically affect older male dogs, and spread quickly in the early stages. It has usually invaded a dog's lymph nodes by the time the condition is discovered.

Symptoms of Oral Cancer in Dogs

The signs of oral cancer in a dog are also signs of dental problems of concern:

  • Bleeding from the mouth
  • Swelling of the face
  • Very bad breath
  • Excessive drooling
  • Chewing food with one side of the mouth due to pain

A veterinarian should be scheduled to make a full oral examination, so any tumors or lumps found can be tested for cancer.

Treatment of Oral Cancer in Dogs

Treatment depends on the location of the cancer and its type. Options include surgery, radiation and chemotherapy. Reconstructive surgery may be necessary if a large amount of tissue or bone has to be removed.


The prognosis of a dog with oral cancer, like the treatment of it, is dependent upon the location, size and type of tumor. Tumors towards the front of the jaw are typically easier to treat, as well as cancers that did not spread. Cancer that is located in the back of the tongue or jaw and tonsils is more likely to spread and harder to kill.

Experts are not sure why dogs develop oral cancer, but suspect it may be due to carcinogens a dog may encounter in his environment. They advise dog owners schedule regular dental check-ups and seek veterinary care when abnormalities are seen in a dog's mouth.