Oral tumors arise from both soft tissue and bony structures within the oral cavity and can include less common locations such as the tongue and tonsils.

They can be either benign and successfully removed and cured with surgical methods or malignant and require more aggressive therapy including chemotherapy and/or radiation. 

Prognosis is dependant on type, size, location, and stage of the tumor.

What is oral cancer?

• Oral tumors arise from both soft tissue and bony structures within the oral cavity and can include less common locations such as the tongue and tonsils.
• Oral tumors comprise 6% of all types of cancers in dogs and approximately 4% of all tumors in the cat.  These are the fourth most common type of cancer in the dog. 
• They can be either benign and successfully removed and cured with surgical methods or malignant and require more aggressive therapy including chemotherapy and/or radiation. 
• General categories of tumors include the epulides (fibromatous, ossifying, and acanthomatous), locally invasive malignant tumors (fibrosarcoma, soft tissue sarcoma, and squamous cell carcinoma), and malignant tumors that have a higher rate of spreading to other parts of the body (melanoma, osteosarcoma). 

Clinical Signs

• There is no breed or sex predilection associated with oral tumors although there is a higher incidence reported in older animals depending on the tumor type. 
• The presenting complaint by the owners is usually that they visualize a lump or mass in the mouth. 
• Other common clinical signs include hypersalivation, bloody oral discharge, halitosis (bad breath), facial asymmetry, and difficulties with eating and drinking to complete anorexia. 
  

Diagnosis

• Preliminary diagnosis is made by visualization of the mass on initial physical examination. 
• A CBC, complete biochemical profile, urinalysis, and three view thoracic radiographs should be performed at a minimum before considering surgical excision. 
• Depending on the size of the mass and its location, a fine needle aspirate or incisional (wedge) biopsy may be warranted.  Again, due to location, sedation would be necessary to obtain a diagnostic sample.  These samples are submitted for histopathological analysis for accurate diagnosis. 
• Oral x-rays may also be taken to determine the extent of the tumor beyond what is visible.  More commonly, a CT of the skull including the affected area is most effective at determining the extent of tumor invasion.  If there is enlargement of any of the lymph nodes, a sample of this will also be submitted.    Once surgery is complete, the entire block of tissue that is removed is analyzed to determine if radiation or chemotherapy is necessary.
  

Treatment

• The gold standard of treatment for oral tumors is surgical excision with wide enough margins to remove all of the tumor plus a border of normal healthy tissue. 
• Removal of any part of the upper jaw bone is called a maxillectomy, while removal of any part of the lower jaw bone is termed a mandibulectomy.  The amount of the jaw that is removed is dependant on the size of the tumor.  There can be instances where one side of the jaw is completely removed if the tumor is large enough.  Despite removing such a large portion of the jaw, the cosmetics are very good in most cases (place your cursor over the photos to see the facial appearance after surgery). 
• Another option for a more normal cosmetic appearance is the harvesting of bone from the hind limb which is then used to rebuild the jaw using special microvascular techniques. Our hospital is one of five in the entire USA that can successfully perform such a procedure in dogs.
  
• Removal of a significant portion of the jaw can result in shortening of the lower jaw and nose.  This may result in a tilting forward producing a Roman type of nose.  There are surgical techniques described to minimize this effect. 

Potential Complications

• By changing the lower jaw conformation, the saliva that is normally produce may accumulate and leak out of the affected side causing a moist but mild dermatitis that is managed with topical therapy. 
• The potential for infection in general is usually fairly low, in spite of the high bacterial population of the mouth.  Appropriate antibiotics are usually prescribed to prevent any overt problems.  Some animals may have a mild reaction to a selected antibiotic seen as vomiting or an upset stomach.  In these instances, switching antibiotics is acceptable.
• Tumor recurrence and spread of the tumor are also potential complications that may require additional treatment.
  

Home Care

• Implicit home care instructions are necessary after surgery to remove oral tumors.  Firstly, feeding a commercially available soft/moist dog food for the first 2-3 weeks should be done. 
• Allowing free access to water after eating is important to try and rinse out the mouth.  Alternatively, using a syringe and either water or an antiseptic dental rinse such as Novaldent, you can physically flush the mouth out after eating.  Once your veterinarian determines that the incisions have healed, a gradual reintroduction to your pet’s regular diet is acceptable. 
• Chew toys and raw hides should be avoided during that time period.  
• Roughhousing with other pets or any extraneous activity which may cause breakdown of the surgical site is discouraged. 
• Generally, the face will appear swollen postoperatively and you can minimize this swelling initially by applying a cold compress to the facial region, 20 minutes per session, four times daily for the first two days. Thereafter a warm compress should be applied to the affected area for 10 minutes at a time three to four times a day.  Continue using warm compresses until the swelling resolves.
  
• Follow up care can be done with your regular veterinarian or a multidisciplinary referral hospital depending on the required course of action. 
• Keep in mind that if a malignant tumor was removed from the mouth, three view chest radiographs should be taken every 3 months from the time of surgery. 
• If adjuvant therapy is required, an appointment with a board certified oncologist should be made for continued care.    
   

Prognosis

• Prognosis is dependant on histopathologic evaluation, location, and size of the tumor in some cases.
• In general, tumors located on the front part of the jaw frequently have a better prognosis.
• Melanomas spread very quickly, but if they are small, curative surgery may be possible.
• Squamous cell carcinomas located in the front part of the jaw tend to have a low tendency to spread. When located in the back part of the mouth (jaw, tongue or tonsils), they have a high tendency to spread.
• Fibrosarcomas tend to have a low rate of spread, but are locally invasive and have a tendency to recur after surgical removal has been performed.
• Osteosarcoma located on the lower jaw (mandible) has a lower incidence of spread and a fair to good prognosis, however, when located on the upper jaw (maxilla) the risk for spread is very high.
• The epulides (including acanthomatous epulis) do not spread to other parts of the body, but can recur if they are not completely removed.