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What is it?
Megaesophagus literally means “big esophagus.” Normally the esophagus, which connects the oral cavity to the stomach for the transport of food, is in a collapsed state. When food is swallowed it is moved through the esophagus which enlarges to accommodate the bolus of food. In the normal functioning esophagus, food moves from the oral cavity to the stomach within a few seconds. Dogs with megaesophagus have difficulty moving the food through the esophagus as a result of a defect in nerve and muscle functioning of the esophagus. Because the esophagus does not function normally, sometimes food does not make it to the stomach. Instead, the food is regurgitated (NOT vomited.) The most common sign seen in pets with megaesophagus is regurgitation of food, usually within minutes of swallowing (although sometimes the food may be regurgitated several hours after eating.) Usually the regurgitated food appear similar to its uneaten state, as it is not digested. Sometimes the food is in a tubular or sausage shape. Other signs which may occur include extreme hunger, emaciation, foul smelling breath, change in voice, and coughing in pets which aspirate food or liquid into the lungs (aspiration pneumonia, a potentially fatal complication of megaesophagus.)
How do dogs get megaesophagus?
There are two forms of megaesophagus, congenital and acquired. In most practices, congenital is the more common form which is seen. Puppies with congenital megaesophagus typically regurgitate as soon as they are introduced to solid food. Breeds of puppies which are predisposed to megaesophagus include German Shepherd dog, Irish setter, Great Dane, Labrador retriever, Shar-Pei, Newfoundland, Fox Terrier, and miniature schnauzer. The cause is unknown but there appears to be a genetic component in some of these breeds. Cats are very rarely affected with megaesophagus; as such this discussion will be limited to the condition as it occurs in dogs.
Acquired megaesophagus is very rare and usually occurs in older pets. Common causes of acquired megaesophagus include hypothyroidism, organophosphate poisoning, Addison's disease, and myasthenia gravis. It is crucial that a cause for acquired megaesophagus be investigated, as treating the cause of the megaesophagus might be curative. If a cause cannot be identified, the condition is called acquired idiopathic megaesophagus.
Dogs with suspected megaesophagus should be evaluated thoroughly and promptly, as the disease can be fatal, especially if aspiration pneumonia occurs. Routine blood and urine testing should be performed in all puppies and dogs; unless a known cause of megaesophagus is present (such as hypothyroidism,) results of these tests will usually be normal. Radiographs of the chest and abdomen can also be obtained and may reveal an enlarged esophagus, possibly filled with air, fluid, or food. Definitive diagnosis is usually made with a barium study of the esophagus or a special radiographic evaluation called fluoroscopy, both of which would reveal an enlarged esophagus. Other testing that can be performed in older dogs with acquired megaesophagus may include blood testing for acetylcholine receptor antibodies and adrenal gland testing as well.
In general, dogs with megaesophagus cannot be cured but are rather managed. There are certainly exceptions to this and I and my holistic colleagues around the world have successfully “cured” a rare number of pets with megaesophagus. In cases of acquired megaesophagus in adult dogs, treating the underlying cause (such as supplying thyroid hormone to pets with hypothyroidism,) if it can be determined, is critical in preventing further damage to the esophagus.
Early in my veterinary training, it was common to euthanize puppies with congenital megaesophagus, as it was felt that there was no hope for these pets to ever recover. Now however, especially when alternative therapies might be helpful, it is always worth trying to save these puppies as many can live relatively normal lives.
All pets with megaesophagus appear to do better when fed small frequent meals, usually from an elevated position to allow gravity to move food through the nonfunctional esophagus. The “best” food to feed will vary among affected pets. Finding the “best” food to feed is a matter of trial and error. Sometimes liquid or soft diets worked best, other times moistened dry food works best, and still other times dry kibble works best.
Drug therapy is usually not rewarding in pets with megaesophagus. Drugs that may be attempted include metoclopramide or cisapride. These drugs are prokinetic agents which have a stimulating effect on the smooth muscle of the gastrointestinal tract. Because the dog’s esophagus is made of skeletal muscle, these drugs generally do not work in our canine patients but can certainly be tried, and may help relax the sphincter between the lower esophagus and the stomach which would be beneficial.
Because there are no conventional medications which are routinely effective in treating dogs with megaesophagus, we must instead rely upon natural therapies. As is the case with conventional medications however, several different approaches may need to be attempted before finding the best solution to the problem.
Acupuncture may be helpful in treating pets with megaesophagus in an attempt to stimulate normal esophageal motility. Additionally, chiropractic manipulation can also be tried in an attempt to remove any blockages that could disrupt nerve supply to the esophagus.
Various herbal, homeopathic, and nutritional supplements might be effective and are certainly worth trying in affected pets. I have had some success combining acupuncture with supplements including homeopathics and whole food supplements.
The Heel corporation recommend several supplements that may be helpful for pets with megaesophagus (based upon treatment of a similar condition called achalasia and people) These include Ypsiloheel, Spascupreel, Atropinum comp, Nux vomica Homaccord, and Gastricumeel. Whole food supplements may also be helpful in include the following from Standard Process: Organic Minerals, Cataplex B, and Paraplex. Supplements such as choline which have a direct positive effect on nerves may also be tried; my favorite products is made by MVP Laboratories and is called Choldin.
While the treatment of megaesophagus is usually not successful in curing pets with this disease, with patience in choosing the best therapy for each pet, including feeding the “best” diet for each pet, many dogs will live relatively normal lives with a condition that was often fatal in years past.
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