Page 420 - Small Animal Internal Medicine, 6th Edition

392 PART III Digestive System Disorders

If vomiting and regurgitation still cannot be distinguished, the latter two clinically mimic each other. Fluoroscopic eval-
plain thoracic radiographs ± a barium-contrast esophagram uation of swallowing a barium meal is necessary to differen-
VetBooks.ir will detect most esophageal lesions. However, some esopha- tiate pharyngeal from cricopharyngeal dysfunction. If they
are not accurately differentiated, inappropriate therapy may
geal disorders (e.g., hiatal hernia, partial stricture, segmental
cause morbidity or mortality.
motility defects) are easily missed unless a careful radio-
graphic technique and/or fluoroscopy is used. Endoscopy is Two main reasons for esophageal regurgitation are
sometimes required to detect esophageal lesions missed by obstruction and muscular weakness. Plain thoracic radio-
imaging (e.g., esophagitis). graphs are the initial step for defining these problems.
Barium-contrast esophagrams are often necessary because
plain films do not detect many esophageal lesions. Using
REGURGITATION liquid barium sulfate can miss partial strictures, but mixing
barium with canned food or kibble typically reveals these
If regurgitation is confirmed, the disease should be localized lesions. Fluoroscopy may be necessary to detect partial loss
to the oropharynx or esophagus (Fig. 26.1). History or of peristalsis, segmental aperistalsis, gastroesophageal reflux,
observing the pet eating should allow the clinician to detect or sliding hiatal hernias. Sometimes the lower esophageal
dysphagia (e.g., undue stretching or flexing of the neck sphincter must be fluoroscopically observed for several
during swallowing, repeated efforts at swallowing, food minutes to detect frequency and severity of gastroesophageal
falling from the mouth during swallowing). Some animals reflux (normal animals may show occasional reflux). If the
with dysphagia associated with neuromuscular disorders animal seems to be regurgitating but contrast-enhanced
have more difficulty swallowing liquids than solid foods, radiographs fail to reveal esophageal dysfunction, either the
probably because it is easier to aspirate liquids. Oropharyn- assessment of regurgitation is wrong or there is occult esoph-
geal dysphagic animals in particular often cough when swal- ageal disease requiring esophagoscopy for diagnosis (e.g.,
lowing water. esophagitis, gastroesophageal reflux).
If a regurgitating animal is dysphagic, then oral, pharyn- Esophageal obstruction is principally caused by foreign
geal, and cricopharyngeal dysfunctions must be considered; objects, vascular anomalies, cicatrix, and tumors. Achalasia

Animal is “vomiting”

History/physical examination

Vomiting Regurgitation Expectoration

Plain thoracic/cervical radiographs

Foreign object Evidence suggestive No foreign objects Obvious megaesophagus
of perforation No evidence of perforation
(pneumomediastinum, some air in esophagus
pneumothorax, mediastinal History, physical History, physical
fluid density, do not fit fit
pleural effusion) Barium contrast radiographs of the megaesophagus megaesophagus
esophagus, using liquid barium and
barium-coated food applying
abdominal pressure
Esophagoscopy or
surgery
Obstruction Weakness Hiatal hernia Uncertain

Acquired Congenital Congenital Acquired Esophagoscopy
Fluoroscopy

Contrast CT Supportive Seek cause
and/or endoscopy treatment (Box 26-5)

Surgery
FIG 26.1
General diagnostic approach to regurgitation in the dog and cat.