Page 479 - Small Animal Internal Medicine, 6th Edition

CHAPTER 29 Disorders of the Oral Cavity, Pharynx, and Esophagus 451

stimulus-producing sustained gingival inflammation. Cats Diagnosis
might have an excessive oral inflammatory response that can Atrophy of temporalis and masseter muscles and inability
VetBooks.ir produce marked gingival proliferation. cian to establish a presumptive diagnosis. Histopathology
to open the dog’s mouth while anesthetized allow the clini-
Clinical Features
(preferably with immunohistochemistry) of the tempora-
Hyporexia and/or halitosis are the most common signs. lis and masseter muscles confirms the diagnosis. Finding
Affected cats grossly have reddened gingiva around the teeth antibodies to type 2M fibers strongly supports this diag-
and/or posterior pillars of the pharynx (the latter is not seen nosis. Animals may have increased serum creatine kinase
with gingivitis). The gingiva may be obviously proliferative (CK) activity.
in severe cases and bleed easily. Dental neck lesions often
accompany the gingivitis. Teeth chattering is also occasion- Treatment
ally seen. High-dose prednisolone therapy (2.2 mg/kg/day) with or
2
without azathioprine (50 mg/m q48h) typically controls
Diagnosis acute disease but is seldom helpful in patients with chronic
Biopsy of affected (especially proliferative) gingiva is needed disease that cannot open their mouths. Once control has
for diagnosis. Histologic evaluation reveals a lymphocytic- been achieved, the prednisolone is administered every 48
plasmacytic infiltration. Serum globulin concentrations may hours and then the dose of prednisolone is tapered to avoid
be increased. Checking for FeLV and FIV infection is impor- adverse effects. However, this tapering must be done slowly
tant, and virus isolation from biopsied tissue may be helpful. to prevent recurrence (see the section on immunosuppres-
sive drugs in Chapter 72). If the mouth cannot be opened
Treatment even under anesthesia, a gastrostomy tube may be used.
There is currently no reliable therapy for this disorder. Proper Although some clinicians have used force to break the adhe-
cleaning and polishing of teeth and antibiotic therapy sions in chronic cases, this approach may cause mandibular
effective against anaerobic bacteria may help. High-dose fracture and is not recommended.
glucocorticoid therapy (e.g., prednisolone, 2.2 mg/kg/day,
methylprednisolone 10-20 mg subcutanenous (SC), triam- Prognosis
cinolone 0.2 mg/kg orally [PO] daily) is often useful. In some The prognosis is usually good for acute cases, but continued
severe cases, multiple tooth extractions (especially premolars medication may be needed.
and molars) may alleviate the source of the inflammation, in
which case it is important that the root and periodontal liga-
ment also be removed. Extraction of the canine teeth should CRICOPHARYNGEAL
be avoided if possible. Immunosuppressive drugs such as ACHALASIA/DYSFUNCTION
chlorambucil or cyclosporine (initially give 2-4 mg/kg PO
bid, but then adjust based upon blood levels) may also be Etiology
tried in obstinate cases. The cause of cricopharyngeal achalasia/dysfunction is
unknown, but it is usually congenital. There is an incoordi-
Prognosis nation between the cricopharyngeus muscle and the rest of
The prognosis is guarded; severely affected animals often do the swallowing reflex, which produces obstruction at the
not respond well to therapy. cricopharyngeal sphincter during swallowing (i.e., the
sphincter does not open at the proper time). The problem
has a genetic basis in Golden Retrievers.
DYSPHAGIAS
Clinical Features
MASTICATORY MUSCLE Primarily seen in young dogs, cricopharyngeal achalasia
MYOSITIS/ATROPHIC MYOSITIS rarely occurs as an acquired disorder. The major sign is
regurgitation immediately after or concurrent with swallow-
Etiology
ing. Some animals become hyporexic, and severe weight loss
Masticatory muscle myositis/atrophic myositis is an idio- occurs. Clinically this condition may closely mimic pharyn-
pathic immune-mediated disorder that affects muscles of geal dysphagia.
mastication in dogs. The syndrome has not been reported in
cats. Diagnosis
Definitive diagnosis requires fluoroscopy or cinefluoroscopy
Clinical Features while the animal is swallowing barium or other contrast
In the acute stages, the temporalis and masseter muscles may media. A young animal regurgitating food immediately on
be swollen and painful. However, many dogs are not pre- swallowing is suggestive of the disorder, but pharyngeal dys-
sented until the muscles are severely atrophied and the phagia with normal cricopharyngeal sphincter function
mouth cannot be opened. must be differentiated from cricopharyngeal disease.