What is Megaesophagus?
Megaesophagus in dogs is the abnormal dilation or stretching of the esophagus with decreased mobility which makes it so the esophagus can’t move food and water down to the stomach. The food and water sit in the chest cavity and esophagus and may cause the dog to regurgitate the contents. Make a note that regurgitation is not the same as vomiting as with vomiting, dogs will gag and retch until throwing up while with regurgitation, the food and water sit in the esophagus and is pushed back up with gravity with no signs prior to doing it.
What Causes Megaesophagus in Dogs?
There are two types of Megaesophagus which have different causes:
Congenital Megaesophagus: This is when dogs are born with the condition due to a birth defect or hereditary/genetic predisposition. Congenital megaesophagus is usually noticed in puppies as they start weaning.
Acquired Megaesophagus: This type is when the condition is brought on by another disease or condition and brought on later in life.
Who’s at Risk of Developing Megaesophagus?
Congenital megaesophagus is often caused by incomplete esophageal nerve development. Fortunately, your dog’s nerve function can improve as they get older. Breeds who have a predisposed risk of being born with congenital megaesophagus include:
- Irish Setters
- Great Danes
- German Shepherds
- Wire-Haired Fox Terriers
- Miniature Schnauzers
- Golden Retrievers
Conditions and diseases that increase the risk of a dog developing acquired megaesophagus include:
- Severe esophageal inflammation
- Brain or spinal cord trauma or degeneration
- Nerve and muscle damage of the esophagus
- Hormonal diseases such as hypothyroidism or Addison’s Disease
- Toxin exposure
- Blockage in the esophagus by either a tumor, scar tissue, or other foreign body
Dogs with peripheral neuropathies, laryngeal paralysis, myasthenia gravis, esophagitis, and chronic or recurring stomach dilatation with or without volvulus are more likely to develop megaesophagus. Dogs with acquired megaesophagus may also have improved function if the underlying condition or disease is treated.
What Are the Symptoms of Megaesophagus?
The first noticeable and most common sign of Magesophagus in dogs is the regurgitation of food and liquid that they just ate or drank causing them to also lose weight or have stunted growth. Other clinical signs of Magesophagus include:
- Bulging at the base of the neck
- Bad breath
- Loss of appetite
- Exaggerated or frequent swallowing
- Extreme hunger
- Excessive drooling
- Aspiration pneumonia
- Nasal discharge
- Increased respiratory noises
How Can Megaesophagus Be Prevented?
Megaesophagus cannot be prevented if a dog is born with it. The most you can do is help prevent possible conditions that may cause megaesophagus.
How is Megaesophagus Diagnosed?
When trying to acquire a megaesophagus diagnosis, the veterinarian will conduct a physical examination and palpitate your dog’s throat. They will collect information about your dog including their medical history and symptoms they’ve been displaying. An x-ray or radiograph may be done to try and detect an enlarged esophagus but that can sometimes be difficult to see. To make it easier, your dog might be given a barium swallow in order to easily see the esophagus during a fluoroscopy, aka a “real-time” radiograph, so the vet can see the mobility of the esophagus as the dog swallows.
A CT myelogram scan is also a form of imaging that might be done. An esophagoscopy may be used to physically examine the interior of the esophagus in which a thin tube-type tool with a light lens is inserted into the esophagus to detect any abnormalities or obstructions.
Other testing includes a complete blood count, biochemistry profile, and urinalysis. While they might not detect the megaesophagus, they may uncover an underlying condition that’s causing it. Other possible tests include:
- Acetylcholine receptor antibody titer
- Cortisol levels test
- Blood lead levels test
What is the Treatment for Megaesophagus?
If a dog has developed megaesophagus as a result of another underlying condition or disease, the first step of treatment would be to treat that underlying condition in the hopes that the esophagus would revert back to normal. The main goal of treatment, especially with congenital megaesophagus is to manage the condition in order to help your dog have a better quality of life. There are multiple ways to treat or manage the condition:
The method of upright feeding allows gravity to move food and water into a dog’s stomach instead of being pushed back up. A common way to do upright feeding is in a chair like this:
This is a special chair for dogs with megaesophagus that allows the food and water to easily pass through the esophagus into the stomach to prevent regurgitation. They have been dubbed “Bailey Chairs” due to the company that originally made and sold the chairs: Baileys Chairs 4 Dogs. They are like high chairs for dogs. You can purchase one from a company like Bailey’s or you can even DIY one! Whether you use a Bailey chair or not, the trick is to get the dog to eat or drink at a 45º angle or more and leaving them in that position for about 10-20 minutes after eating or drinking. One way to do this is using a step ladder that’s about 2 or 3 steps (this can vary depending on the height of the dog) and placing the bowls on the top of it.
Type of Food
The texture and consistency of your dog’s food can also help but this might take some trial and error to see what your dog responds to the best. Some examples that have helped dogs include forming wet food into meatballs or softening food with liquid into a soup consistency. Dogs with megaesophagus can also benefit from a high-calorie diet due to the inability to keep food down so they can at least get more calories out of what they do eat. They may also benefit from 3-4 smaller meals a day instead of just 2 larger ones.
There are various prescriptions medications for megaesophagus including:
You may know this medication by a different name: Viagra. But how can a dog with megaesophagus benefit from it? Sildenafil opens the sphincter between the stomach and esophagus and helps move food from the esophagus into the stomach.
Sucfrafalate helps heal and protect the esophagus from the stomach acids that go through the esophageal tract when a god regurgitates.
A couple of types of motility modifiers include Metoclopramide and Cisapride. They stimulate muscles in the gastrointestinal tract and help keep the stomach closed so food doesn’t come back up.
Surgery may be done to help treat or manage the underlying condition or disease such as removing a foreign object or tumor in the esophagus.
What is the Prognosis for a Dog With Megaesophagus?
Unfortunately, the prognosis isn’t great for dogs with megaesophagus whether they have treatment or not but that is another thing that can be dependent on the cause as well as the severity due to the complications. But if treatment can help improve esophageal function then the prognosis also increases. Dogs who undergo treatment and have their megaesophagus managed can still live a full, happy life.