Hey, pet parents. Today we're going to talk about a challenging and unusual condition called Megaesophagus. This is a disorder of the esophagus (the tube that carries food from the mouth to the stomach) that can make it very difficult for a dog to eat and drink normally. Let's get a handle on this condition.
What is Megaesophagus?
Normally, when a dog swallows, the muscles of the esophagus contract in a wave-like motion (called peristalsis) to push the food down into the stomach.
In a dog with megaesophagus, the esophagus loses its muscle tone and becomes enlarged and floppy, like a stretched-out balloon. Without normal muscle function, the food and water just sits in the esophagus instead of being pushed into the stomach.
This isn't a problem with swallowing itself, but rather with the transport of food after it has been swallowed.
What Causes Megaesophagus?
Megaesophagus can be either congenital (present at birth) or acquired later in life.
- •Congenital Megaesophagus: Some puppies are born with the condition. It often becomes apparent around the time they are weaned onto solid food. In some breeds, like German Shepherds and Great Danes, it is known to be hereditary.
- •Acquired Megaesophagus: In adult dogs, megaesophagus is often "idiopathic," meaning we can't find an underlying cause. However, it can also be secondary to other diseases, the most common of which is Myasthenia Gravis, a neuromuscular disease. It can also be associated with other conditions like Addison's disease or certain toxins.
Spotting the Signs: Vomiting vs. Regurgitation
The number one, hallmark sign of megaesophagus is regurgitation. It is absolutely critical to understand the difference between regurgitation and vomiting.
- •Vomiting is an active process. The dog will be nauseous, they will heave, and their abdominal muscles will contract forcefully to expel the contents of the stomach.
- •Regurgitation is a passive process. There is no heaving or nausea. The dog simply lowers its head, and out comes undigested food and water from the esophagus. It can seem to happen without any warning at all.
Other signs of megaesophagus include:
- •Regurgitating undigested food: The food often comes back up still in the shape of the kibble or in a tube-like shape.
- •Weight loss and poor growth: Because the food never makes it to the stomach to be digested.
- •Coughing or difficulty breathing: This is a sign of the most dangerous complication of megaesophagus: aspiration pneumonia.
Aspiration Pneumonia: The Biggest Risk
Because the food and water sits in the esophagus, it can easily be accidentally inhaled into the lungs. This can cause a severe and often life-threatening pneumonia. The signs of aspiration pneumonia are coughing, fever, difficulty breathing, and lethargy.
How Vets Diagnose Megaesophagus
The diagnosis is usually made with a chest X-ray. On the X-ray, the esophagus will be visibly enlarged and filled with air, fluid, or food. Sometimes, your vet will give your dog a liquid contrast material (like barium) to swallow, which will highlight the enlarged esophagus on the X-ray.
Once megaesophagus is diagnosed, your vet will recommend further tests (like bloodwork to check for Myasthenia Gravis or Addison's disease) to look for an underlying cause.
Treatment and Management: It's All About Gravity
There is no cure for idiopathic megaesophagus. The management of the condition is focused on one main goal: getting the food from the mouth to the stomach without it sitting in the esophagus. And the key to this is gravity.
Managing a dog with megaesophagus requires a huge amount of dedication from the owner.
- •Upright Feeding: The dog must be fed in a completely vertical position. This allows gravity to do the work that the esophagus can't. Owners will often use a special high chair, called a "Bailey Chair," to hold the dog in an upright, "begging" position during meals.
- •Staying Upright After Meals: After eating, the dog must remain in the upright position for 20-30 minutes to make sure all the food has made it into the stomach.
- •Food Consistency: The best food consistency can vary from dog to dog. Some do best with a liquid slurry, while others do better with soft, meatball-like chunks of food. It often takes some trial and error.
- •Multiple Small Meals: It's best to feed several small meals throughout the day rather than one or two large ones.
- •Medications: Some medications can help to improve the emptying of the stomach, but there are no drugs that can make the esophagus contract normally again.
If an underlying cause like Myasthenia Gravis is found, treating that disease can sometimes resolve the megaesophagus.
Prognosis
The prognosis for dogs with megaesophagus is variable. The biggest risk to their life is aspiration pneumonia. Some dogs have repeated bouts of pneumonia and have a poor quality of life. However, many other dogs, with incredibly dedicated owners who master the art of upright feeding, can live long and happy lives.
Caring for a dog with megaesophagus is a true labor of love, but for the right owner, it can be a very rewarding journey.
Sources & Further Reading:
- •VCA Animal Hospitals - Megaesophagus in Dogs
- 1Canine Megaesophagus Info - A great resource for owners