Diagnosing & Treating Benign Oral Tumors in Dogs

benign oral tumors in dogs - man and woman with their pet dog

Diagnosing & Treating Benign Oral Tumors in Dogs

The diagnosis of an oral mass in a pet can be a frightening thing for a pet owner. However, the majority of oral tumors in dogs tend to be benign, meaning they are often less aggressive and do not spread to other regions of the body like a malignancy. Most of these benign oral growths have an excellent prognosis and can be successfully removed with surgery.  

What is a Canine Epulis?

Historically, a growth on the gum tissue was referred to as an epulis in veterinary medicine. “Epulis” is a nonspecific, all-inclusive term for any swelling or growth on the gingiva (gum tissue), palatal tissue and oral mucosa. However, this term is very general and does not relay any specific information regarding the growth other than its location on the gum tissue. In veterinary dentistry, this term does not have any real use for common benign oral tumors and should not be used. 


Oral Masses in Dogs

A benign oral mass may be as simple as a small bump on the gum tissue or it may be larger, displacing teeth or resulting in the destruction of the underlying bone. Along with a proper diagnosis, the size and location in the oral cavity are vital to surgical planning. When complete surgical excision of these growths is possible, the recurrence rate is extremely low and considered curative. 

In comparison, malignant oral tumors tend to be much more aggressive and destructive at the site of the tumor. These masses also have the potential to spread to other parts of the body like the lymph nodes, lungs, liver, or other organs. However, there are still many treatment options for malignant oral tumors that can result in a cure and return to an excellent quality of life. 

Diagnosing Benign Oral Tumors

A descriptive appearance of the growth is not enough information for a diagnosis or to formulate a treatment plan. More information is always needed. Diagnostic imaging (dental radiographs or cone beam CT scan) is used to characterize the extent and invasiveness of the growth into surrounding tissue and bone. Incisional biopsies allow for tissue analysis including microscopic identification and diagnosis of the growth. 

At Animal Dental Care and Oral Surgery, we always recommend biopsies be performed. However, the initial biopsy should not be used as an opportunity to remove the growth at the first visit the vast majority of the time. Initial biopsy samples should almost always be incisional, meaning only a small sample piece of the tumor is removed. This allows for a definitive treatment plan that will hopefully result in a cure since the surgeon knows exactly what type of tumor they are removing. 

Treating Common Benign Oral Growths

Once a diagnosis has been made a surgical plan can be formulated. The size of the growth and its location influence the surgical plan. With a complete surgical excision, these odontogenic tumors have little to no recurrence. The most common benign oral growths diagnosed in the oral cavity of dogs are: (1) benign overgrowth of normal gingival tissue, aka, Focal Fibrous Gingival Hyperplasia; (2) peripheral odontogenic fibromas; and (3) canine acanthomatous ameloblastomas. These 3 different growths make up the vast majority of benign growths submitted to veterinary pathology labs for identification.  

1. Focal Fibrous Gingival Hyperplasia

This is the most commonly diagnosed benign gingival growth. These are growths that result from an increased number of normal cells in tissues of the gingiva. The result is a gingival overgrowth. Underlying causes include periodontal disease, genetic/breed predispositions, and different medications, such as some anticonvulsants, cyclosporine, or Calcium channel blocking drugs. Treatment consists of surgical excision of the excess gingiva/growth and addressing any underlying cause.   

2. Peripheral Odontogenic Fibroma (POF)

These are the most common odontogenic tumors diagnosed in dogs. Odontogenic refers to tumors that are derived from the developmental tissues of the tooth. They are slow-growing and tend to be isolated to the gingival tissue. These tumors are not considered to be locally aggressive and are not associated with the destruction of the underlying bone. Recurrence is minimal with complete excision and demonstration of clean surgical margins. The tissue that is removed does have to be quite large in order to completely remove the tumor. 

3 Canine Acanthomatous Ameloblastoma (CAA)

These are the second most common odontogenic tumor diagnosed in dogs. They are more aggressive, compared to POF’s. These tumors infiltrate into surrounding tissue and do cause destruction of the underlying bone. Although complete excision is curative, surgery may be more challenging based on the location and size of the mass. Surgical margins need to be larger and always involve the removal of part of the surrounding bone along with any associated teeth. 


Not all gingival growths are the same and identification is key before any surgical treatment should be performed. The three benign oral growths discussed in this article can look similar but differ significantly in their biologic behavior. Diagnosis based on visual appearance is not possible and must be made using diagnostic imaging and tissue biopsies. Once this information is collected surgical planning can take place. 

At Animal Dental Care and Oral Surgery in Colorado Springs, our Board-Certified Veterinary Dentists take every step to properly diagnose and treat both malignant and benign oral tumors in dogs. With our state-of-the-art technology, advanced surgical techniques, and vast experience, we assure you that your beloved pet is in good hands.

Photo by Chewy on Unsplash (11/24/2020)