Acanthomatous Ameloblastoma in Dogs

Short-nosed breeds such as the pug are more susceptible to acanthomatous ameloblastoma.
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Canine acanthomatous ameloblastoma is a tongue-twister of a clinical name for one of three related kinds of benign growths that occur in a dog's mouth. Together, these growths are often classified as epulid tumors, or epulides. In oncology, benign means that a tumor doesn't spread, or metastasize, throughout the body from its place of origin, so technically, it isn't cancer. But benign doesn't mean harmless, especially where acanthomatous ameloblastoma is concerned. These tumors "have characteristics of malignancy," notes "The Textbook of Internal Veterinary Medicine," and getting rid of them requires equally aggressive treatment.

What the Tumor Looks and Feels Like

It's wise to inspect your dog's mouth regularly and if you spot a lump or irregularity, get it checked out by a veterinarian. The epulides are the most common benign oral tumors in dogs, but canine acanthomatous ameloblastoma is the most aggressive of the three. If left untreated, it will invade bone and tissue. Even though acanthomatous ameloblastoma itself isn't malignant, it's considered precancerous, meaning if it isn't removed, it's apt to turn malignant. Check your pup's gumline as these tumors are typically seen around incisor and canine teeth. They feel firm to the touch but the surface might have a bumpy, cauliflower-like appearance. Usually but not necessarily, there's only one.

Signs, Symptoms and Vulnerable Breeds

Dogs of any age and breed can develop acanthomatous ameloblastoma but the tumors are most often seen in dogs age 7 or older, and certain breeds are more susceptible than others. According to Ryan Veterinary Hospital at the University of Pennsylvania, Shetland and old English sheepdogs appear to be predisposed. Since these tumors often develop at trauma sites, brachycephalic, or short-nosed, breeds such as bulldogs, pugs, Pekingese, boxers, Boston terriers and shih tzus are disproportionately affected because upper and lower jaw misalignment often allows their teeth and gums to rub against each other. In addition to a lump, signs may include drooling, bad breath, chewing difficulties, weight loss, bleeding from the mouth and facial deformity.

Making a Diagnosis

Numerous types of malignant and benign oral tumors affect dogs but you can't tell merely by looking at a growth in a dog's mouth what kind it is, says the American Veterinary Dental Association. Even though some features of a tumor might suggest a certain diagnosis, these signs are inconsistent, so confirmation requires microscopic examination of biopsied tissue. After that, X-rays, MRIs or CT scans may be used to determine the size of the growth and to what extent it has impacted the surrounding tissue and bone.

Surgery, Radiation and Chemotherapy

If acanthomatous ameloblastoma isn't treated aggressively, tumors will continue to destroy bone and tissue, ultimately affecting a dog's ability to eat, according to veterinary oncologist Kim L. Cronin of the New England Veterinary Oncology Group. Removing enough of the tumor to stave off regrowth often entails cutting away part of the jawbone along with adjoining teeth and gum tissue. Radiation has been shown to be effective when used either in combination with, or in place of, surgery, although larger tumors tend not to respond as well, Cronin says. Reportedly, chemotherapy has had some success in treating acanthomatous ameloblastoma, although multiple sessions are necessary and undesirable side effects sometimes occur, John Lewis, assistant professor of dentistry and oral surgery at Ryan Veterinary Hospital, wrote in "Veterinary Practice News" in January 2012.