Oral tumors are relatively common in dogs and cats, but may not be noticed at an early stage by pet owners. Not all enlargements of the tissues in the mouth are tumors. Examples include gingival hyperplasia, localized infections, and collections of saliva from damaged or diseased salivary glands. Tumors may be benign or malignant. Benign tumors do not spread to other parts of the body and generally grow more slowly than malignant tumors although they can be locally destructive. Malignant tumors invade the adjacent tissue and can spread to other parts of the body. Not all tumors appear as a “typical” visible growth. Some present as non-healing, ulcerated areas.
Radiography is an essential part of assessing tumor characteristics, in particular the extent of the tumor and the presence of bone involvement. Careful evaluation of your pet's radiographs may make it possible to associate different patterns with certain tumor types, and/or suggest a benign or malignant (aggressive) lesion. Other advanced diagnostic imaging techniques may be indicated in some cases. Tumors located in the back of the mouth often require computed tomography (CT) to visualize the extent of the tumor. Good diagnostic imaging is especially important in correctly planning a pet's surgical procedure.
The type of tumor cannot be determined accurately based on radiographs alone, and biopsy is always required for definitive diagnosis. Proper management of a pet patient with an oral tumor starts with accurate diagnosis. While the visual appearance and location of an oral growth can often give clues as to its identity, confirmation of the diagnosis (and thus an accurate prognosis and identification of appropriate treatment) requires biopsy. All oral growths should be investigated. A “wait and see” approach is not recommended.
Biopsy may be incisional (taking a small portion for microscopic examination, with no attempt to remove all of the swelling) or excisional (surgery to remove the tumor completely). The biopsied tissue is sent to a pathologist. If the veterinarian feels an abnormality of one of the lymph nodes in the neck, biopsy or needle aspiration of the abnormal lymph node may be recommended.
For most pet oral tumors, surgical removal offers the best chance of cure. Surgery may need to be radical (removal of part or all of a jaw, for example) in order to provide the best chance for complete removal of the tumor. Dogs tolerate radical surgery very well. Because there are so many types of oral tumors that can occur in dogs and cats, each with a different prognosis, management by a veterinary dental specialist or oncologist is recommended. Your regular veterinarian may take a biopsy and then refer the case to a specialist.
The key to successful treatment of oral cancer in a pet is early detection of the growth. Owners who are in the habit of brushing their pet’s teeth every day are likely to note changes in the mouth earlier. For owners not brushing their pet's teeth daily, a weekly oral inspection is recommended. When a swelling in the mouth is noted, seek a consultation with a veterinary dentist as soon as possible.