Diagnosing Oral Cancer in Dogs

Mouth cancer in dogs is more frequently met in older dogs and can evolve at a fast rate or slower, depending on the type of tumor. The melanomas are the most common mouth cancers in canines and these will develop quickly, affecting the gums and the bones. Oral cancer in dogs can be diagnosed using the symptoms, the appearance of the tumor and by running a few tests. The biopsy is the most important test that needs to be performed when cancer is suspected.

Symptoms of Cancer in Dogs

A tumor in the dog's mouth may be located in various places and in some cases, the tumors may be visible. Most commonly, you will find tumors in the periodontal ligament area. These tumors are known as epulids.

You can inspect the dog's mouth. The tumors may be felt as lumps, which may be solid or filled with liquid, depending on the type of cancerous cells that are present. A dog that has mouth cancer may present the following symptoms:

  • Excessive drooling
  • Lack of appetite or hesitance to eat, as the tumor may hinder the dog from swallowing
  • Bad breath, different from the normal breath of the dog
  • Mouth bleeding, which may be less significant (i.e., you may spot a few drops of blood in the dog's saliva), but may be more serious also
  • Swelling of the face or areas of the face
  • Chewing only on one side, as the dog will avoid chewing on the affected side

These symptoms can also signal the presence of a dental problem or gum disease, so a number of tests should be performed.

Differentiating between Benign and Malignant Tumor

There are two types of tumors that can affect the dog's mouth. The benign tumors (fibromas) are not cancerous, while the malignant tumors (melanoma, squamous cell carcinomas) are dangerous for the dog's overall health.

The benign tumors may look just like the malignant tumors, especially during the incipient stages of the tumor. However, benign tumors may be more symmetrical, have regular angles, only one color and will not grow in time. The malignant tumors are typically more aggressive, have several colors and may also have an irregular shape.

In any case, a biopsy is necessary to tell the difference between benign and cancerous cells and the biopsy may only be performed by a vet.

Clinical Tests

In addition to the biopsy, which will tell the difference between a benign and a malignant tumor and the composition of the tumor, the vet will also perform additional tests. Malignant tumors will typically affect the bone and gums and will spread in the mouth and to the closest lymph nodes. Some tumors will be more aggressive (melanomas). X-rays and ultrasounds will be performed to assess whether the tumor has spread and to determine if surgery is possible. Blood tests can also help the vet determine the general state of the pet, which is important when determining the best course of action.