Epulis

# 1 -What is an epulis?

An epulis is the most common benign tumor of the mouth in dogs. It is usually located in the gum tissue near the incisors or canine teeth. It originates in the connective tissue that holds the teeth to the bone of the jaw. The literal translation of "epulis" is "gum boil."

There are three types of epulides (the plural for epulis):

Fibromatous: Consists of tough, fibrous tissue.
Ossifying: In addition to fibrous tissue, also contains bone cells. These may transform into cancerous tumors.
Acanthomatous: More invasive, growing into the normal bone around it and destroying it, but not metastasizing.

What causes an epulis?

The cause of epulides is unknown, but they do occur more commonly in older dogs and Boxers. They occur equally in both sexes.

What signs are associated with an epulis?

Usually, the owner simply notices a firm growth between the teeth. The tumor is usually the same color as the gum tissue, has a smooth surface, and may be attached to the gum via a peduncle (a stalk-like structure). As the epulis enlarges a dog may drool, have difficulty eating or lose his appetite, have bad breath, bleed from the area of the tumor, or even have trouble breathing depending upon the size and location of the tumor. It may push apart and misalign the adjacent teeth. There is often more than one epulis present.

How is an epulis diagnosed?

An epulis may be suspected by its location and appearance, but it is necessary to biopsy the tumor to distinguish if from other oral tumors. A pathologist will examine the tissue microscopically to determine if it is an epulis, and of what type. Other oral tumors include squamous cell carcinoma (malignant), and other benign tumors such as fibromas, lipomas, and histiocytomas.

How is an epulis treated?

Surgery is necessary to remove the epulis. A wide margin (large portion of healthy tissue around the tumor, possible including some bone) needs to be taken to assure all of the epulis is removed. If a portion remains, it will often regrow. The teeth next to the epulis usually need to be removed, as well. Large epulides may also be treated with radiation.

What is the prognosis for a dog with an epulis?

If the epulis is small and all of the tumor is removed, the prognosis is good. The larger the tumor, the more likely a recurrence or complications. Acanthomatous epulides have a more guarded prognosis since they are much more difficult to completely remove. On rare instances, radiation therapy has resulted in the tumor becoming cancerous.

Certain viruses are able to cause the growth of small round skin tumors that are commonly referred to as warts. Everyone who has every seen a drawing of a fairy tale witch knows what warts look like so when the family dog develops small round skin growths, many people assume these are harmless warts. In reality, there are many types of small round skin growths and it is important for them to be examined as some such growths may not actually be innocuous viral warts. Most growths must be removed and biopsied before they can be identified, though in some cases the viral papilloma has an obvious appearance and can be identified visually.

Dogs actually can get viral warts, but not from the same viruses that cause human warts. Dogs do not get warts from people, and people can’t get warts from dogs.

In dogs, we do not call these growths “warts;” we use the more formal term “viral papilloma.” These are benign skin tumors caused by the canine oral papillomavirus.

Viral papillomas are round but often have a rough, almost jagged surface reminiscent of a sea anemone or a cauliflower. They occur usually on the lips and muzzle of a young dog (usually less than 2 years of age). Less commonly, papillomas can occur on the eyelids and even the surface of the eye or between the toes. Usually they occur in groups rather than as solitary growths.

The infection is transmitted via contact with the papillomas on an infected dog. The incubation period is 1-2 months. This virus can only be spread among dogs. It is not contagious to other pets or to humans. To become infected, the dog generally needs an immature immune system, thus this infection is primarily one of young dogs and puppies. Beyond this, transmission details are sketchy. It is not known whether the infected dog must actually show visible lesions to be contagious, nor how long after regression of lesions contagion is still of concern.

Not really. They should go away on their own as the dog’s immune system matures and generates a response against the papillomavirus. There have been two cases published where viral papillomas progressed to malignancy but this is extremely rare and by no means the usual course of the infection. Typically, it takes 1-5 months for papillomas to regress with oral growths tending to regress sooner than ocular growths. Occasionally some papillomas will stay permanently.

Sometimes oral papillomas can become infected with bacteria of the mouth. Antibiotics will be needed in such cases to control the pain, swelling, and bad breath.

In most cases, treatment is unnecessary; one simply allows the papillomas to go away on their own. Occasionally an unfortunate dog will have a huge number of tumors, so many that consuming food becomes a problem. Tumors can be surgically removed or frozen off cryogenically. Sometimes crushing several growths seems to stimulate the host’s immune system to assist in the tumor regression process. In humans, anti-viral doses of interferon have been used to treat severe cases of warts and this treatment is also available for severely infected dogs. Sometimes some of the warts can be removed and made into a “vaccine” which is felt to stimulate the immune system in removing the tumors, though such vaccines do not seem to be as effective as one might want. Obviously such treatments should be performed by a veterinarian; do not attempt freezing, cutting or crushing of growths on your own.

Gardner, DG. Epulides in the dog: A review. Journal of Oral Pathology & Medicine 25:32-7, 1996.

Howard, P. Neoplasms of the maxilla and mandible. In Birchard, SJ; Sherding, RG (eds.) Saunders Manual of Small Animal Practice. W.B. Saunders Co. Philadelphia, PA; 1994: 957.

Maretta, SM. Recognition and treatment of oral tumors. Presented at the Atlantic Coast Veterinary Conference, Atlantic City, NJ. October 9-11, 2001.

Spodnick, GJ; Page, RL. Canine and feline oropharyngeal neoplasms. In Bonagura, JD (ed.) Kirk's Current Veterinary Therapy XII. W.B. Saunders Co. Philadelphia, PA; 1995.