Page 36 - BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, 2nd Edition

Chapter 3
VetBooks.ir

Surgery of the oral cavity

and oropharynx

Alexander M. Reiter and Mark M. Smith

Introduction • Saliva may be blood-tinged in animals with ulcerated
lesions
Surgery of the oral cavity and oropharynx is required to • There may be increased plaque accumulation and this,
treat neoplasia, traumatic and congenital lesions, and in addition to necrosis of tumour tissue, may result in
diseases affecting the lips and salivary glands. These prob- halitosis.
lems are addressed in this chapter. The reader is referred
to the BSAVA Manual of Canine and Feline Dentistry and Diagnosis and staging
Oral Surgery for complementary information on the surgical
The diagnosis is based on histopathological examination.
treatment of small animal dental and oral surgical diseases.
Advances in the development and application of immuno-
histochemical techniques in veterinary medicine may pro-
Oral tumours vide methods for early detection of malignant neoplasms
(Stromberg et al., 1995; Gamblin et al., 1997; Oliver et al.,
1997; Ramos-Vara et al., 2000). Staging of the disease
Oral tumours are common in dogs and cats. They may be
of dental or non-dental origin. In dogs, periodontal liga- should be considered as an active investi gative process to
be performed in concert with the diagnostic evaluation.
ment tumours, malignant melanoma and squamous cell
carcinoma (SCC) are most commonly diagnosed. In cats, A complete blood count, biochemistry profile and urin-
the predominant tumours are SCC and fibrosarcoma alysis should be reviewed to determine organ abnormalities
related to metastatic or concurrent disease, which would
(Harvey and Emily, 1993).
Predisposing factors include patient age, sex, breed, alter the anaesthetic protocol or preclude the use of
size and pigmentation of oral mucosa. Geriatric patients are general anaesthesia. Thoracic radiography or computed
generally predisposed; however, fibrosarcoma has been tomo graphy (CT) is used to evaluate metastasis to the lung.
reported to occur more frequently in young, large-breed The size of the neoplasm is more accurately assessed
dogs. Viral papillomatosis and undifferentiated malig- after administration of general anaesthesia. Radiography,
nancies may also be included in the differential diagnosis CT or magnetic resonance imaging (MRI) of the head can
for young dogs with oral masses. Papillary SCC, previously be performed during anaesthesia to provide information
thought to be a tumour in young dogs, is now considered to on the extent of local tissue invasion. Regional lymph
be a very well differentiated form of SCC whose occurrence node enlargement indicates either metastasis or reactiv-
is not dependent on age. Male dogs have been reported to ity related to oral inflammation. Regardless of size, lymph
be at higher risk for malignant melanoma and fibrosarcoma. nodes should be evaluated by fine-needle aspiration (NB:
Breeds with an increased risk for oral neoplasia, irre- false-negative results are possible) or excisional biopsy.
spective of type, include German Shepherd Dogs, Short- A surgical approach was developed to provide exposure
haired Pointers, Weimaraners, Golden Retrievers, Boxers for excisional biopsy of ipsilateral parotid, mandibular
and Cocker Spaniels. Large-breed dogs have a higher and medial retropharyngeal lymph nodes through a single
incidence of fibrosarcoma and non-tonsillar SCC, whilst incision (Smith, 1995). A negative lymph node biopsy
smaller breeds have a higher incidence of malignant mela- does not preclude the possibility of regional metastasis,
noma and tonsillar SCC. Dogs with heavily pigmented oral which may occur along the perineural or vascular routes,
mucosae are predisposed to malignant melanoma (Harvey or metastasis to other less accessible lymph nodes.
and Emily, 1993). Many oral neoplasms are detected late in the disease
process owing to their location deep in the oral cavity.
Clinical signs Consequently, oral malignancies have usually progressed
to at least stage II disease at the time of diagnosis. Higher
Clinical signs associated with oral neoplasms depend on staged malignant tumours are associated with a poorer
size and location: prognosis.

• Food prehension may be abnormal Biopsy
• Secondary traumatic ulceration may occur in animals
with larger neoplasms Biopsy is indicated for all oral masses, unexplained lesions
• Inability to swallow or associated pain may result in and autoimmune diseases with oral manifestation. The
drooling biopsy sample should always be taken from a location

BSAVA Manual of Canine and Feline Head, Neck and Thoracic Surgery, second edition. Edited by Daniel J. Brockman, David E. Holt and Gert ter Haar. ©BSAVA 2018 27

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