Esophageal Problems in Dogs and Cats

Esophageal problems in dogs and cats
Introduction

The esophagus, or gullet, is normally well protected by squamous epithelium with tight junctions and mucus containing bicarbonate ions. Note that the musculature of the canine esophagus is striated along the entire length of the esophagus, whereas in cats (and humans), the bottom 30-50% of the esophagus is composed of smooth muscle. This means that some diseases, such as the focal form of myasthenia gravis, can cause esophageal signs in dogs. Regurgitation is often the only clinical symptom that is noted in dogs and cats with esophageal problems. Because regurgitation is a very important clue for localizing the problem to the esophagus, it is important to distinguish between dysphagia (difficulty in swallowing) and true vomiting (see table 1). Dysphagia is often accompanied by retching, salivation, and food or fluid loss, and this is suggestive of an oral or pharyngeal cause. If an animal is vomiting, which is an active discharge of food or fluid from the stomach or the proximal duodenum, there will be a visible abdominal effort, and affected animals often show nausea, salivation and retching before vomiting. Regurgitation, however, is a passive retrograde passage of undigested food or liquid without abdominal effort. […]