According to the American College of Veterinary Surgeons (ACVS), benign and malignant tumors of the oral cavity account for 3% to 12% of all tumors in cats, and 6% of all tumors in dogs, so these masses are relatively common in pets. Unfortunately, most tumors in the mouth are not only malignant, but also aggressive, and can cause severe local damage. Metastasis may also occur, affecting the lungs, spleen, and other organs. 

Oral tumors can affect any part of your pet’s mouth, and harm the upper and lower jaws, tongue, cheeks, the hard and soft palates, mouth floor, lips, and gums. Since there are no definitive causes of oral cancers in pets, early detection is critical for thwarting the effects of a malignant mass. The best way to monitor your furry pal’s oral health is through daily toothbrushing, which not only keeps your pet’s teeth and gums healthy, but also enables you to keep an eye out for any abnormalities that develop, and take prompt action.

Some common oral tumors in pets include melanoma, squamous cell carcinoma, and fibrosarcoma. To help pet owners learn to recognize potential signs of these cancers, our Animal Dental Clinic team has compiled key facts you need to know, to keep your furry friend healthy. 

Oral melanoma in dogs

Melanoma is the most common oral tumor in dogs, affecting, on average, dogs around 11 years old. Oral melanoma is a locally invasive tumor, burrowing deep into the bone, and metastasizing in up to 80% of dogs, according to reports. Oral melanoma signs in dogs include:

  • Increased salivation
  • Facial swelling
  • Dropping food
  • Weight loss
  • Bad breath
  • Inability to eat
  • Loose teeth

 If the tumor has spread to the lymph nodes, swellings under the jaw and in front of the shoulders may develop. Lung metastases, displayed by coughing, lethargy, and inappetence, are common.

Some melanomas can be diagnosed through a fine-needle aspirate, where Dr. Weldon will take a sample from the tumor with a needle and syringe. However, most oral tumor fine-needle aspirates require sedation or anesthesia. A biopsy, which requires general anesthesia, may also be necessary to confirm the diagnosis, and ensure adequate surgical margins.

After staging the melanoma’s severity through blood work, X-rays, and possibly an abdominal ultrasound, we form a treatment plan. In general, surgery and radiation therapy are recommended for tumor removal, and chemotherapy for any metastatic cells. The smaller the tumor, and the closer to the front of the mouth, the better the prognosis.

Fibrosarcoma in dogs

Fibrosarcomas in dogs form in the oral cavity’s fibrous tissues, and are locally invasive, but only about one-third metastasize. Oral fibrosarcomas may appear as swollen areas anywhere inside the mouth. They frequently ulcerate, and may also become infected. 

Common fibrosarcoma signs in dogs include:

  • Swelling inside and outside the mouth
  • Oral pain
  • Bad breath
  • Excessive drooling
  • Panting
  • Discomfort while eating 
  • Dropping food
  • Inappetence 

Unlike some other cancer forms, fibrosarcomas are not easily diagnosed with a fine-needle aspirate, and often require a biopsy for a definitive diagnosis. These tumors can be aggressive, despite a low malignancy grade, which means treatment should also be aggressive for the best prognosis. Surgical removal of the tumor may include removing part of the jaw, but recurrence is still possible. These tumors do not respond well to chemotherapy or radiation alone, so a multi-modal treatment plan is the best course of action, often pairing surgery with radiation therapy.

Squamous cell carcinoma in cats and dogs

Squamous cell carcinoma is the most common oral tumor in cats, and the second most common in dogs. An oral squamous cell carcinoma is a tumor of the cells that line the digestive tract, and affects the gum line, tonsils, and oral cavity. Smoke exposure, and the use of flea collars, have been identified as significant risk factors for squamous cell carcinoma in cats, but no such correlation has been found  in dogs.

Squamous cell carcinoma lesions may appear as thickened, plaque-like areas, or look more cauliflower-like. These masses can occur anywhere in the mouth, and may break open and bleed. Oral pain is common, especially in pets with tumors that have penetrated the underlying bone, which may cause signs such as excessive salivation, panting, bad breath, inappetence, and difficulty eating. 

These tumors, like other masses, are diagnosed using a fine-needle aspirate or biopsy. Once an accurate diagnosis has been achieved, we can begin treatment, which consists of surgically removing the tumor, and potentially part of the jaw. Depending on how much of the tumor was excised, your pet may also need radiation or chemotherapy, to battle any remaining cancerous cells. 

Routine dental care is vital for catching oral tumors early in your pet, before they create serious issues. Schedule your best friend’s comprehensive oral exam at our Animal Dental Clinic, to ensure their mouth is in great health.