Malignant oral tumors

Small Animal Section: No. 2

NON-ODONTOGENIC MALIGNANT ORAL TUMOURS IN DOGS AND CATS : BIOLOGICAL BEHAVIOUR, TREATMENT & PROGNOSIS

Aim of this communication

	To summarise the biological behaviour of the most common malignant oral tumours in dogs and cats
	Provide general guidelines on treatment and prognosis

Key facts

	Tumours of the oral cavity constitute the 4th most common neoplasms in dogs
	Oral neoplasia represents 10% of all tumours in the cat, and approximately 90% of these are malignant
	Some oral lesions and growths that are not neoplastic can mimic tumours; e.g. feline eos granuloma
	Lesional biopsies are essential to diagnose primary oral disease; deep biopsies are necessary because superficial biopsies may reveal only superficial inflammation or gingival hyperplasia

Behaviour, treatment and prognosis of some non-odontogenic malignant oral tumours

Below we tabulate the prevalence, biological behaviour and prognosis of the more common malignant tumours and summarise approaches to treatment

Tumour	Prevalence	Biological behaviour	Treatment	Prognosis
Malignant melanoma	Most common oral tumour in dogs	Grows rapidly; necrosis and ulceration are common; and 70-90% metastasise	Radical surgery; chemotherapy for metastatic disease	Small tumour rostral & low mitotic index better prognosis. High metastatic rate
Squamous cell carcinoma DOG: Non-tonsillar or glossal	2nd most common oral tumour in dogs	Locally invasive, metastasis uncommon	Radical surgery; orthovoltage radiation; or combination	Rostral positioning associated with better prognosis
Squamous cell carcinoma CAT: Non-tonsillar or glossal	Most frequent oral malignancy in cats	Locally invasive and may invade bone; metastasis rare	Radical surgery; combined with orthovoltage radiation	Apart from rostral mandible, guarded-poor
Fibrosarcoma	Frequently in young dogs	Infiltrative tumour, grows rapidly, frequently recurs after surgery, may infiltrate bone, and has a 35% change of metastasis	Radical surgery; radiation	1 yr. survival good Recurrence affected by surgical technique

Other tumours of the oral cavity include

Epulides and odontogenic oral tumours - refer to leaflet no. 1 of our series in the small animal section

Papilloma; haemangioma and haemangiosarcoma; osteosarcoma

Round cells tumours : lymphoma, mast cell tumour, TVT, extramedullary plasmacytoma

Recent publications on oral tumours

	The Compendium Vol 20 (9): 1011-1020 & Vol 20 (10): 1109-1115 (1998).
	Canine and feline oropharyngeal neoplasms; Current Veterinary Therapy XII, 691-695 (1995)

For further information contact:

VetPath Veterinary Pathologists
P.O. Box 8464
Pretoria 0001
Tel: (012) 529 8345/6
e-mail: info@vetpath.co.za

Dr Gerard Steenkamp
Dental Clinic (Cape AMC, Joh Animal Eye Hosp, OP)
P.O. Box 610
Magaliesig 2067
Tel: (011) 465 1237; Cell: 082 8093845

For any animal pathology queries, please send e-mail to info@vetpath.co.za.
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Copyright © 2004 Bill Robb & Associates
Last modified: Friday June 25, 2004