Oral Tumors in Dogs and Cats

Medical articles

The mouth is a complicated place. There is a lot going on in there, which can sometimes mean a lot can go wrong too. Oral tumors in dogs and cats can begin in both soft places (gums, tongue) and hard places (bones, teeth).

Forms of Oral Cancer

The bad news is that most oral tumors are cancerous:

  • In dogs, the most common oral cancers are malignant melanoma and  squamous cell carcinoma.

  • In cats, the most common oral cancer is squamous cell carcinoma.

Other cancers can also take root in the mouth, including osteosarcoma (“bone” cancer) and mast cell tumors (found more often in a pet’s skin) as well as others.

There are a couple of common benign oral tumors with scary sounding names. As one of my veterinarians likes to say, “Eyes are not microscopes,” so the only way to know for sure is to biopsy – often surgically -- an oral growth or area of swelling.

Oral Tumor Symptoms

Having just gone through this with one of my dogs, I can tell you that oral tumors feel like they come out of nowhere. One day, everything seems okay, the next you notice something scary.

In addition to swelling in the mouth, or even in your pet’s face or muzzle, you may notice some changes that might indicate a problem:

  • A lump or bump

  • Drooling

  • Bad breath

  • Bleeding

  • Bulging eye

  • Bloody nasal discharge

  • Difficulty eating, swallowing, or opening the mouth

  • Loose teeth, in an otherwise healthy mouth (more common in cats)

Oral Tumor Treatment

Veterinarians typically recommend surgery. Often the surgery required is significant, even invasive, to ensure clean margins around the tumor. The problem is that these oral cancers often grow in a tentacle-like fashion, sending little offshoots of cancer in several directions.

Your main veterinarian will likely refer you to a board-certified veterinary surgeon if you choose surgical treatment for an oral tumor. In some cases, your veterinary oncologist may advise additional post-operative radiation and chemotherapy.

Outcomes vary based on the kind of cancer and the stage at which it’s found.