Salivary Gland Tumors in Dogs and Cats

By: Dr. Al Townshend

The salivary glands secrete saliva, which plays a vital role in digestion, chewing, and swallowing food. There are four major pairs in dogs and cats; parotid, mandibular, sublingual, and zygomatic. 

Tumors are not common but are almost always malignant. They generally occur in older animals (10 years old or more). There is no sex or breed predisposition. 

The most common tumor occurs in the parotid gland (located by the base of the ear) in dogs and the mandibular gland (located at the level of the lower jaw) in cats. 

What are the signs?

The most consistent sign is a swelling at the base of the ear or lip. Pets may also have bad breath, difficulty chewing or swallowing, and begin drooling. As the disease progresses, listlessness, inappetence, and weight loss develop, and the pet may be unable to open its mouth completely. Difficulty swallowing may also occur.

How are salivary glands diagnosed?

A complete physical exam, x-rays, lab tests, CT scans, MRIs, and biopsies can all be used to make the most accurate diagnosis and make the best decisions after the diagnosis.

How are salivary gland tumors treated?

While benign tumors such as adenomas do occur, the most common type of primary tumor in dogs and cats is an adenocarcinoma, a highly malignant form of cancer. Because it has a high probability of spreading, treatments may not always be advisable. 

  • Palliative care to control pain and maintain the best quality of life for as long as possible may be the best choice.

– To learn more about palliative care, check out https://kaliswish.org/end-of-life-petcare/ 

  • Surgery to remove the gland and tumor completely or partially is the most common recommendation. Benign growths have a good chance of being removed completely. Malignant adenocarcinomas are very invasive and difficult to remove completely, so radiation is often used after surgery. 
  • Chemotherapy does not work well with this form of cancer.

What is the prognosis?

Benign tumors have a good prognosis, while malignant adenocarcinomas have a poor prognosis. 

If you do suspect a tumor in your dog or cat, it’s best to consult your veterinarian to understand what’s really happening.

If you are facing a diagnosis, Kali’s Wish is here to help! Learn more about our free programs and services on our Homepage, and visit our Health Hub for more pet cancer resources.

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