What Is Megaesophagus?

Megaesophagus is a medical condition found in dogs, cats, horses and humans. Relatively rare in cats, but common in dogs, megaesophagus (ME) occurs when the esophagus (the fibromuscular tube that transports food from the mouth to the stomach) becomes abnormally enlarged.

A normal esophagus is narrow, with 2 valves (called sphincters) at each end. When food is swallowed, it’s propelled downward through the esophagus into the stomach by a series of muscular contractions. Once the food safely reaches the stomach, the valves close, keeping both food and stomach acid in the stomach where they belong.

In cases of megaesophagus, however, the esophagus loses all muscle tone and dilates. It fills with air and loses its ability to push food downward. The swallowed food then just sits in the esophagus until it is eventually regurgitated.

Regurgitation is not the same as vomiting. Vomiting is an active process that uses the contraction of abdominal muscles to bring food up from the stomach. Regurgitation, however, is passive. With regurgitation, swallowed food that never reaches the stomach sits in the esophagus until it simply falls back out through the mouth. Since regurgitation often happens within minutes after eating, the food often comes back up looking completely intact.

Megaesophagus is a serious condition. Not only does it prevent food from reaching the stomach (which can literally cause a pet to starve), but regurgitated food can accidentally be sucked into the trachea, or airway, and enter the lungs. This results in an inflammatory lung condition called aspiration pneumonia, which the most common reason pets die from this disease.

Symptoms of Megaesophagus

The primary symptom of megaesophagus is regurgitation of food and water, usually fairly quickly after eating. Other symptoms may include:

• Weight loss (due to food never reaching the stomach)
• Extreme hunger
• Difficulty swallowing
• Drooling
• Coughing
• Changes in vocal tone
• Bad breath
• Nasal discharge
• Fever
• Poor body condition/haircoat
• Respiratory distress (caused by aspiration of food into the lungs)

What Causes Megaesophagus?

Pets with ME typically fall into 2 groups: those with congenital ME (which usually occurs during the first few months of life), and those with the acquired form (which usually occurs in older pets).

Congenital megaesophagus can result from a problem with the development of esophageal nerves, or from a remnant of a fetal artery that wraps around the esophagus, preventing food from passing through.

Acquired megaesophagus may be caused by several different diseases that cause nerve damage, including myasthenia gravis (a disease that interrupts the way nerves communicate with muscles), Addison’s disease (a deficiency of cortisone in the the body), or hypothyroidism (abnormally low activity of the thyroid gland). Myasthenia gravis is the most common cause of megaesophagus, with 25% of ME dogs testing positive for this disease.

Prognosis is better for congenital megaesophagus than it is for the acquired form. However, many cases of megaesophagus have no known cause.

Breeds Predisposed To Megaesophagus

Although any dog or cat can develop ME, there are certain breeds who seem to be genetically predisposed:

Dogs

• Great Dane
• Irish Setter
• Newfoundland
• German Shepherd
• Shar pei
• Labrador Retriever
• Golden Retriever
• Miniature Schnauzer

Cats

• Siamese
• Persian

Other dog breeds that seem to experience a higher-than-normal frequency of ME include:

• Bernese Mountain Dog
• Boston Terrier
• Corgi
• Dachshund
• French Bulldog
• Greyhound
• Irish Wolfhound
• Rottweiler
• Wire-haired Fox Terrier

How Is Megaesophagus Diagnosed?

Most patients with megaesophagus are large breed dogs, between 5 and 12 years of age.

The first step in diagnosing ME is to take radiographs of the chest. An enlarged esophagus is easily seen on x-ray, as well as any signs of pneumonia from aspirating regurgitated food. A dog or cat with megaesophagus who also has nasal discharge, cough, and fever will be immediately suspected of having aspiration pneumonia.

In some cases, barium (a metallic liquid) can be used to make the esophagus show up better on x-rays, but some veterinarians try to avoid using barium since it has to be swallowed – and barium aspirated into the lungs can cause problems.

Endoscopy, where a long, thin tube with a camera on the end is passed down the esophagus and into the stomach, can also be used for diagnosis. Blood tests can also be done to rule out the presence of other diseases (such as those mentioned earlier) that can cause megaesophagus.

The difficult part of diagnosing ME is not identifying the enlarged esophagus itself, but determining the underlying cause of the enlargement. However, since most cases of ME have no apparent cause, those cases must be managed just as they are.

Unfortunately, this can be hard work – but it can be done.

Management of Megaesophagus

Megaesophagus can’t be cured with surgery or medication. However, it can be managed by reducing regurgitation, which consequently reduces the risk of the pet developing aspiration pneumonia and assures that the pet’s nutritional needs are being met.

There are several strategies for managing megaesophagus in dogs:

Feeding from a height

This technique uses gravity to help move food downward into the stomach. A step stool can be used by placing food on the top platform of the stool and allowing the dog to eat with his forefeet on the upper steps and his back feet on the ground.

Many people use a “Bailey Chair” to feed dogs with megaesophagus. The Bailey Chair was invented by the owners of an ME dog named Bailey. It looks much like a human highchair that holds the dog in an upright position while he eats.

Since Bailey Chairs must be custom-made for each individual dog, many people construct their own. They are fairly simple to make. The family who created the Bailey Chair provides video instruction (along with additional information about dogs with megaesophagus) on their website.

Those with smaller dogs can be more creative. Some people use human highchairs packed with pillows to hold the dog in place, some use baby slings, and others simply hold the dog upright with its back to the owner’s chest while the dog eats.

Feeding the right type of food

Food consistency is critically important for dogs with megaesophagus. Most of these dogs cannot tolerate dry kibble (hard, crunchy particles in the throat is bad news), so high-quality canned food, or a slurry of kibble soaked in water and blended, works best.

Some dogs who don’t tend to chew their food do better with “meatballs” made from canned food and cooked oatmeal. The food is blended together, formed into small balls, and firmed in the refrigerator or freezer. Then they are “popped” into the dog’s mouth, and go right down the throat.

Two other things worth noting about diet: first, high-fat diets may make regurgitation worse, so many veterinarians recommend a low-fat, low-fiber diet for dogs with megaesophagus. Second, a raw diet is not recommended for dogs with ME. Since the immune systems of these dogs are already compromised, they may not be able to tolerate the level of bacteria in raw foods.

Elevation of the body after eating

Ideally, dogs with ME should be kept quiet and in an upright position for 15 to 30 minutes after each meal. This is where the Bailey Chair is particularly handy.

Many dogs regurgitate at night while they’re laying down. For dogs who sleep in a crate, the front of the crate can be elevated a few inches to keep their heads slightly higher than their hindquarters. Dogs can also be trained to sleep with their heads and shoulders on a large pillow.

Timing of feedings

Dogs with megaesophagus need to be fed multiple, small meals during the day to avoid overloading the esophagus with food.

Use of medication

There are several medications which increase the movement of food through the digestive system that may help dogs with ME. One is metoclopramide (also known as Reglan), which is effective but  can have some negative side effects. Other drugs include cisapride (which is no longer commercially available in the U.S. but can still be made in compounding pharmacies), bethanechol (which improves muscle contraction and nerve strength of the esophagus), or low doses of erythromycin (an antibiotic that speeds up stomach emptying).

Over the counter acid neutralizers such as Pepcid (famotidine), Prilosec (omeprazole) or Zantac (ranitidine) can also help by decreasing the acidity of stomach contents.

Ensuring sufficient water intake

All dogs need a minimum of 1 ounce of water per pound of body weight daily (more if the weather is warm or they are very active). Water can be particularly hard to keep down for dogs with megaesophagus, and they can quickly become dehydrated.

One helpful trick for increasing water intake is to include water in homemade treats. Here are 2 simple recipes that can help supplement water intake:

“Chicken Jelly” (Recipe courtesy of Jaime Powell ¹):

• ½ cup low sodium chicken broth
• 1 ½ cups water
• Thick It (sold in pharmacies)

Thick It is designed for humans with swallowing disorders, and is sold in most pharmacies. This mixture will be a soupy consistency.

“Chicken Jello”:

• 1 cup cold low-sodium chicken broth
• Stir 4 packages of Knox gelatin into broth
• Add 3 cups of boiling water and stir until dissolved

Pour liquid into a 9 × 15 casserole dish and refrigerate until solid, approximately 2–3 hours, then cut into dice-sized cubes.

Use of a feeding tube

In more severe cases, a gastric feeding tube can be used for pets who are unable to keep food down. This tube allows food to be delivered directly into the stomach without having to pass through the esophagus.

The feeding tube is surgically placed in the stomach while the pet is under anesthesia. It exits the body through the side, wherever is most comfortable for the pet. A protective bandage is used daily, and a clamp prevents the leakage of stomach contents. Food is administered as a puree or blended slurry through the tube.

Although feeding tubes can be lifesaving for many pets with ME, precautions must be taken. Bandages around the tube must be changed daily, and constant monitoring is needed to ensure the tube stays in place and does not become infected.

Megaesophagus Is No Longer A Death Sentence

Some veterinary schools still consider megaesophagus a terminal condition, and some students are taught that affected dogs should be euthanized immediately. Although it’s true that ME is a very serious condition, and most dogs with this disorder will have a shortened lifespan, many dogs whose condition is managed properly can live long and happy lives. Bailey (of Bailey Chair fame) lived to the age of 13, ironically succumbing not to megaesophagus, but to lung cancer.

Pets with megaesophagus need to be constantly monitored for aspiration pneumonia (which can occur in a matter of hours and is life-threatening), and pet parents must be diligent about making sure their ME dog or cat gets enough calories and maintains a healthy weight. Since pets with megaesophagus are considered to have weakened immune systems, many veterinarians do not recommend giving them vaccines other than those which are absolutely necessary. Anesthesia can also be risky for pets with this disorder.

It may take lots of trial and error to find the right management techniques that work best for each individual pet. However, many options now exist for pets diagnosed with megaesophagus that didn’t exist even 10 years ago. Each pet parent needs to make their own decisions based on what’s best for their pet – their ability to provide daily care, as well as their pet’s overall quality of life.

¹ Special thanks to Jaime Powell for creating the publication “A Guide To Megaesophagus”, copyright 2011.

Have you ever had a pet with megaesophagus? Please tell us about it in the comments below!