Diseases & Conditions
What is megaesophagus?
Megaesophagus literally means an enlarged esophagus. The esophagus is the muscular tube forming the passageway from your dog’s throat to his stomach. When food enters the esophagus, the muscle contracts and expands to push food into the stomach. With megaesophagus, the esophagus loses its ability to contract and expand effectively. Megaesophagus is classified as either congenital megaesophagus – a hereditary condition – or adult-onset megaesophagus.
Megasesophagus is a serious condition that requires ongoing commitment and management from you and your veterinarian. Dogs with megaesophagus frequently also develop aspiration pneumonia.
What will megaesophagus look like in my dog?
Your dog will regurgitate or aspirate small or large amounts of food, and, if the condition is not addressed, your dog will appear malnourished. The regurgitation observed with this disease is most often confused with vomiting. Vomiting is an active process – when a dog vomits he is actively using abdominal muscle to push food out. In regurgitation as seen with megaesophagus, the food just falls out of your dog’s mouth without him having to force it out as with vomiting. In some puppies with congenital megaesophagus, if you lift the puppy by his back legs you can see the enlarged esophagus protruding from the side of the puppy’s neck.
How does my dog get megaesophagus?
Congenital megaesophagus, the hereditary type of megaesophagus, occurs in puppies. Congenital megaesophagus generally will be first noticed when your puppy begins to eat solid food. It is most common in German Shepherds, Irish Setters, and Great Danes. Congenital megaesophagus is caused either by a developmental abnormality in the nerves of the esophagus or by a condition known as vascular ring anomaly. With vascular ring anomaly, a ribbon of tissue composed of fetal blood vessels which normally disappear before birth surround the esophagus and prevent it from constricting and expanding successfully.
Adult onset megaesophagus is caused by nerve damage to the esophagus triggered by another disease or conditions. Common diseases and conditions that can cause megaesophagus include myasthenia gravis, hypothyroidism and hypoadrenocorticism.
How is megaesophagus diagnosed?
Blood tests to rule in or out treatable causes of megaesophagus should be performed. Your veterinarian will have to take either an x-ray of your dog’s chest or a fluoroscopy (an x-ray that captures movement) of your dog eating his food mixed with some barium liquid. The barium liquid will allow the veterinarian to track the food as it travels through your dog’s esophagus to evaluate his condition. The veterinarian will also take blood to see if there is an underlying condition that might either be causing megaesophagus or masking itself as megaesophagus.
Finally, your veterinarian will want to perform and endoscopy of the esophagus. Through the endoscopy, the vetrinarian will be able to see if the esophagus is constricted, and if there are any ulcers, scarring, tumors or lesions on the esophageal walls. The veterinarian will also perform lung radiographs to assess if aspiration pneumonia has occurred.
How is megaesophagus treated?
Medical therapy consists of feeding your dog soft food in small meatball-like or gruel portions while your dog is standing in an elevated position (head higher than body) so gravity assists in keeping the food in the stomach. Your dog should stay in this position for 15 to 20 minutes after feeding. Medications such as motility drugs are also used to help move food along.
How is megaesophogus prevented?
Treating diseases as soon as possible before the secondary megaesophagus develops is the only known prevention.
Can I get megaesophagus from my dog?
No, you cannot contract megaesophagus from your dog.