Megaesophagus in Dogs: Causes, Symptoms, Treatment & Prevention
Also known as esophageal dilation, megaesophagus is a disease that causes the esophagus (the tube that carries food and liquid between the mouth and stomach) to dilate (get larger) and lose motility (the ability to move food into the stomach).
When your dog’s esophagus is functioning properly, nerves are stimulated in his mouth when he eats, sending signals to the swallowing centre of his brainstem. Those signals trigger his swallow reflex.
When esophageal motility is decreased or absent, food and liquid have difficulty getting into the stomach, and instead collect in the esophagus.
There are two types of megaesophagus:
Congenital megaesophagus: a developmental condition that causes regurgitation. It begins when puppies and kittens start weaning off mom’s milk and begin to eat solid food.
- Acquired megaesophagus: occurs later in a dog's life. It can present in young adults and middle-aged pets (cats, too).
The most important ongoing complication for megaesophagus patients is the risk for aspiration pneumonia.
Regurgitation is not the same as vomiting.
Vomiting is an active process. The body gags, heaves and retches as abdominal muscles forcefully expel stomach contents.
Regurgitation is a passive process. The body spits up food from the esophagus or stomach without the forceful contractions of the abdominal muscles. Regurgitation is a key sign of megaesophagus.
What causes megaesophagus in dogs?
More common in dogs than cats, canine megaesophagus is known to be hereditary in certain breeds, including wire haired fox terriers and miniature schnauzers.
Other breeds that may be predisposed to megaesophagus are:
- German shepherd
- Great dane
- Irish setter
- Labrador retriever
Siamese cats are also sometimes predisposed to megaesophagus.
Myasthenia gravis (damage between the nerves and muscles of the esophagus) is the most common cause of megaesophagus. It occurs in roughly 25% of dogs with acquired megaesophagus. It’s likely the first co-morbid condition your vet will consider.
Some forms of acquired megaesophagus occur alongside other diseases or conditions, such as:
- Degeneration or trauma in the brain or spinal cord
- A blockage of the esophagus by a foreign body, tumor, or scar tissue
- Severe inflammation of the esophagus
- Hormonal disease (ie: hypothyroidism or hypoadrenocorticism—aka Addison's disease)
- Exposure to a toxin
If your dog has acquired megaesophagus, treating the underlying condition can greatly improve (if not eliminate) the megaesophagus.
Congenital megaesophagus is typically caused by incomplete nerve development in the esophagus. Fortunately, as your dog matures, his nerve development can improve.
What are the symptoms of megaesophagus?
Regurgitating food and water is the most common symptom of megaesophagus in both dogs and cats.
Additional symptoms of megaesophagus may include:
- Bad breath
- Fever, rapid breathing, abnormal lung sounds caused by aspiration pneumonia
- Muscle weakness and deterioration caused by malnutrition and/or starvation
- Drooling caused by hypersalivation (an excessive production of saliva)
- Gurgling sounds when swallowing
- Bulging at the base of the neck when attempting to swallow
Pets with megaesophagus tend to act as though they're hungry, but they don’t eat. Instead they just push food around the bowl because they’ve learned to associate eating with coughing and gagging.
Diagnosing megaesophagus in dogs & cats
If your vet suspects megaesophagus in your pet, he’ll take an x-ray to see if the esophagus is dilated. He’ll also look to see if the trachea (your pet’s windpipe) is displaced (not where it should be) due to the buildup of food, liquid and/or gas (or air) in the esophagus.
If the x-rays are inconclusive, your vet will try a contrast medium (like barium) to get a better view of the esophagus.
Other tests may include:
- fluoroscopy or endoscopy to view the inside of the esophagus
- electrical tests to evaluate the connection between the nerves and muscles
- a nerve/muscle biopsy
- evaluation of cerebrospinal fluid (surrounding the brain and spinal cord)
Megaesophagus treatment & prevention
There is no cure for megaesophagus in dogs and cats. Still, the condition may be manageable.
Treating megaesophagus means treating the underlying cause (if there is one). It also means treating any conditions caused by the megaesophagus (like aspiration pneumonia).
Liquid or solid food?
Pets with megaesophagus tend to need a high-calorie diet because they have difficulty keeping food down. But there are things you can do to help.
Figure out if your pet does better on a liquid or solid diet.
Different food consistencies will benefit different pets. For instance, breaking down food in a blender might decrease the chance of regurgitation, but it could also increase the risk of aspiration (inhaling it into the lungs).
On the flip side, some pet parents create “balls” of food, which can stimulate enough esophageal motility to successfully move the food into the stomach.
Upright feeding options
Last, but certainly not least, is the Bailey Chair. You may have heard of it. It’s also known as a “doggy high chair” or “dog feeding chair.”
Specifically designed for dogs with megaesophagus, the Bailey Chair holds your pup in an upright position while he eats. This position minimizes the risk of regurgitation and choking because gravity helps move the food from the esophagus and into the stomach.
You can order a Bailey Chair online or make one yourself. Here’s a handy guide to help you build a Bailey Chair at home.
Not ready for the Bailey Chair? No problem, you have other options for upright feeding.
Some pet parents find that using a small stepladder (2 or 3 steps) leading up to a platform of food works well. This design also forces your pup to stand in an upright position while he eats, using gravity to move food where it belongs, through the esophagus and down in the stomach.
It's best if pets remain in the upright position for 10 to 15 minutes after eating to make sure all the food and water has successfully gravitated down into the stomach. It can be trickier to convince your pet to stay on the steps when they’ve finished eating, so you may have to hold them gently in that position afterwards.
Medications for megaesophagus
Your vet may prescribe a medication to help with his megaesophagus. Among the more popular options are:
Sildenafil - yep, it’s Viagra. Medications can have all kinds of uses, though, and reactions vary greatly between humans and animals. Sildenafil opens the sphincter (the ring of muscle) between the stomach and esophagus, which helps food move from the esophagus into the stomach.
Motility modifiers, like Metoclopramide and Cisapride, stimulate muscles in the gastrointestinal tract. Simply put, these medications help keep the stomach closed so food isn’t spilled back out into the esophagus where it can be regurgitated.
When food comes back up from the stomach to the esophagus, it brings acid with it. That can cause damage to the esophagus, making the condition even worse. Your vet may prescribe a medication called Sucralfate, which can protect and help the esophagus heal from damage caused by stomach acid.
Managing megaesophagus takes some extra care and dedication, but it’s certainly doable. Preventing regurgitation and aspiration is key. Talk to your vet about all your treatment and prevention options.
Want to make sure your pup is getting all the nutrition he needs? Adding a supplement can do the trick. Here are some formulas trusted by your fellow pet parents: