a primer on megaesophagus in pets
If you think back to the blog where we covered the difference between vomiting and regurgitation, you may remember that we mentioned megaesophagus as one of the underlying causes for regurgitation.
What is megaesophagus?
The esophagus is the tube that runs from the mouth to the stomach, delivering food and liquids for digestion. It is made up of smooth muscles, which work together to move food reflexively towards the stomach. Another reflex keeps pets (and us humans, too) from breathing during this time so that food and liquids are not accidentally inhaled.
When the reflex that causes the smooth muscles in the esophagus to contract is disrupted, the esophagus loses its tone and becomes dilated and flaccid. Similarly, when the reflex that keeps us and our pets from breathing while swallowing is disrupted, aspiration pneumonia can easily occur. We’ll touch on that in a bit – first let’s talk more about megaesophagus.
When the esophagus is large and flaccid, food and liquid have the tendency to just sit there in the esophagus after being swallowed, never quite making it to the stomach. Because of this, food and liquid are easily regurgitated.
When swallowing, or upon regurgitation, animals with megaesophagus are prone to accidentally inhale their meal because the reflex that prevents this is disrupted. When pets inhale, or aspirate, food and liquid meals, pneumonia may occur. In pets with megaesophagus, aspiration pneumonia can prove fatal.
Megaesophagus can be a congenital problem, meaning that it is present at birth, or it can be acquired as an adult. Puppies and kittens with congenital megaesophagus have incomplete nerve development. Often, the symptoms of megaesophagus are not seen until the affected pets are weaned and start eating dry food. Nerve development may improve as these pets age.
Acquired megaesophagus is very frustrating. Sometimes there is an underlying cause, such as thyroid disease, esophageal scarring, or in cats, a condition called feline dysautonomia. But in most cases, there is no clear cause. Large breed dogs between the ages of 5 and 12 years are most commonly affected, as are certain breeds, such as Shiloh Shepherds and Bouvier des Flandres, to name a few.
Megaesophagus is diagnosed based on clinical and radiographic signs. X-rays will show a large esophagus and possibly accompanying aspiration pneumonia.
How is it treated?
If an underlying cause is present, treatment of that condition may lead to resolution of megaesophagus. But for those cases where an underlying cause is not found, management of megaesophagus can prove difficult. Feeding a soft or liquid diet, and feeding the affected pet from an elevated bowl can help the food reach the intended target (the stomach) easier. Placement of a feeding tube into the stomach will bypass the esophagus altogether and may be a surgical option.
Megaesophagus is a frustrating disease to deal with, both for owners and veterinarians. Having pet insurance that is able to cover megaesophagus, like Petplan, can allow you to concentrate on your pet's treatment rather than the veterinary bills. If your pet has been diagnosed with megaesophagus, you and your veterinarian will work together to determine the best course of action to provide the best possible quality of life for your pet.