Page 481 - Small Animal Internal Medicine, 6th Edition

CHAPTER 29 Disorders of the Oral Cavity, Pharynx, and Esophagus 453

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FIG 29.1
Lateral contrast radiograph of a Boston Terrier showing esophageal deviation, which is
normal in brachycephalic breeds.

FIG 29.2
Lateral contrast thoracic radiograph of a cat. Note large diverticulum suggestive of
obstruction (arrows). This cat had generalized esophageal weakness without obstruction.

been relatively mild or intermittent, the diagnosis might prevent further dilation and aspiration. The animal is fed
not be made until the animal is older, but a careful his- from an elevated platform that requires the pet to stand on its
tory should suggest that disease has been present since the rear legs making the cervical and thoracic esophagus nearly
animal was young. Endoscopy is not as useful as contrast vertical so that gravity aids food passing through the esopha-
radiographs for diagnosing this disorder. In general, only gus and into the stomach. This position should be maintained
very severe esophageal weakness may be diagnosed endo- for 5 to 10 minutes after the animal has finished eating and
scopically (Video 29.1). Collies may have dermatomyosi- drinking. There are devices (e.g., “Bailey chair”; see http://
tis, which also causes esophageal weakness. Some breeds petprojectblog.com/archives/dogs/megaesophagus-and-the-
(e.g., Miniature Schnauzer, Great Dane, Dalmatian, Chinese bailey-chair/) that aid the owner in keeping the patient ver-
Shar-Pei, Irish Setter, Labrador Retriever) appear to be at tical while feeding. Feeding several small meals a day also
increased risk. helps prevent esophageal retention.
Gruel is usually recommended, but some animals do
Treatment better if fed dry or canned dog food. It is impossible to
Congenital esophageal weakness currently cannot be predict what consistency of food will be best for a given dog;
cured or resolved by medical therapy, although cisapride therefore, trial and error are necessary. In some dogs the
(0.1-0.5 mg/kg) occasionally ameliorates signs (probably dilated esophagus may partially return to normal size and
because it increases lower esophageal sphincter [LES] pres- function. Even if the esophagus remains dilated, some dogs
sure in patients with substantial, concomitant gastroesopha- may be well managed by dietary/feeding modification and
geal reflux). Dietary/feeding management is used to try to have a good quality of life.