The esophagus is a small hose-like tube that leads from the mouth to the stomach. From the mouth, it follows a straight path through the neck and chest, where it passes near the heart, then through the diaphragm muscle and finally enters into the stomach. The esophagus wall is composed of muscles that move in wave-like contractions to push food into the stomach. It takes about five seconds for a cat's food to move from the mouth to the stomach.
A megaesophagus occurs when the esophagus has lost its muscle tone. Rather than appearing like a muscular hose, it dilates into a thin, flacid, 'bag-like' tube. Most cases are congenital
and are probably caused by an inadequate nerve function due to the improper development of the esophageal nerve supply.
What are the symptoms?
The cat tends to regurgitate or vomit food shortly after eating. The diseased esophagus lacks the muscular tone to move food to the stomach. Ingested food is swallowed, but sits within the esophagus until regurgitated back up. Some food, particularly liquids, may pass into the stomach.
What are the risks?
Usually, a megaesophagus is a permanent situation. Sometimes an infection or irritation of the nerve supply may cause temporary symptoms, but this is rare. Megaesophagus is generally a permanent condition that must be dealt with.
What is the treatment?
Congenital megaesophagus has no known cure. Cats affected must be fed liquid diets. The food is usually placed in an elevated position so the cats eat while standing on hind limbs. This elevated eating stance allows gravity to help the liquid food get to the stomach. With these methods, many cats can survive and do well.
Surgery to the esophagus is always difficult because of the location within the chest and its poor rate of healing.