Introduction
This session will deal with the commonly seen neoplasms of the oral cavity and those conditions that look like tumors but
arise from an outside source. Oral tumors arise from the gingiva, buccal mucosa, tongue, mandible, maxilla, palate, dental
structures or tonsils.
Breed and species disposition
The oral cavity is the 4th most common site of malignant neoplasia in dogs and cats.1 The three most common oral tumors in dogs are malignant melanoma, nontonsillar squamous cell carcinoma and fibrosarcoma.
Oral tumors occur 2.6 times more often in dogs than cats and 2.4 times more often in male dogs than females. 10% of all tumors
in cats are seen in the oral cavity with 90% of those oral tumors being malignant. The age disposition for tumors of the oral
cavity is commonly seen in geriatric patients with the exception of oral fibrosarcoma which can be seen in young large breed
dogs. Common breed disposition for oral tumors is Cocker Spaniels, Poodles, German Shepherds, German Shorthaired Pointers,
Weimaraners, Golden Retrievers, and Boxers.2
Clinical symptoms
Patients will present with the following symptoms: dysphagia, halitosis, hemorrhage, ptyalism, anorexia, sneezing, ocular
or nasal discharge, pawing at the mouth, facial swelling, tooth displacement, thickening of the bone of the maxilla or mandible,
exophthalmos and pain. In the case of malignant oral tumors, by the onset of clinical symptoms the stage of the tumor can
be quite advanced.2
Neoplasms from trauma
Gum chewers syndrome
This syndrome is caused by mechanical trauma. The pet chews on the inside of its cheek or tongue. This causes a proliferative
granulomatous hyperplasia to occur at the site. If the chewing is mild the damage will be low. In extreme cases, the lesions
can become large, bleed regularly and cause pain.3
Neoplasms from infectious agents
Gingival hyperplasia
Gingival hyperplasia is a proliferation of the tissue of the attached gingiva. It may occur due to an inflammatory response
such as dental plaque or calculus. The excessive gingival tissue can form what's called a "false pocket" – the extra tissue
increases the depth of the sulcus. The hyperplastic tissue is usually benign. Treatment consists of treating the underlying
periodontal disease and a gingivectomy to remove the excess tissue. This condition can be an inherited trait in certain breeds
such as Boxers, Great Danes, Collies, Dobermans, and Dalmatians.4
Pyogenic granuloma
These lesions result from irritation of a specific site on the gingiva. The gingiva proliferates the area with granulation
tissue. This irritation can be a foreign body or an infected wound. Removing the irritant will usually remove the lesion.4
Feline eosinophilic granuloma
These are chronic progressive lesions which involve not only the lips and the oral cavity, but the skin as well. It occurs
most often in 3 year old spayed cats. The lesions are large, ulcerated, erythematous and raised. The causes have been anything
from grooming to the idea that it is an immune mediated disease. However, this disease is contagious to other cats which suggest
an infectious agent as the cause. A biopsy should be taken to rule out neoplasia or autoimmune disorder. Treatment consists
of decreasing doses of steroids, but recurrence is common. Radiation and cryosurgery have yielded the best results.1,4
