The esophagus (the tube at the pharyngoesophageal junction that leads to the stomach) actively transports food and water from the throat to the stomach through peristalsis, when functioning normally. This neurologic reflex is stimulated by the detection of food and water by the esophagus, subsequently resulting in coordinated sequential muscle contraction and relaxation of the esophagus. This process also stimulates other reflexes that simultaneously close off the airways preventing food and water to not be inhaled into the respiratory tract.
What is Megaesophagus?
With megaesophagus in dogs, also known as “Mega-E”, the reflexes responsible for peristalsis are dysfunctional. This is a lifelong condition. Megaesophagus can be genetic in origin (idiopathic) or triggered by disease in the gastrointestinal system, esophageal tissue disease, or by nerve disease. When this occurs, the active transport of food and water is interrupted, and the esophagus loses tone and becomes dilated. The reflexes that help protect the airway are also dysfunctional.
What happens when your dog has megaesophagus
The inability to transport food actively into the stomach results in food accumulating in the esophagus. This leads to food spilling out of the esophagus and is known as regurgitation. In other words, your dog won’t be able to keep their food down.
Because the reflexes of the airway are also non-functional, this often results in aspiration pneumonia.
Regurgitation vs. Vomiting
It is important to note that there is a distinction between regurgitation and vomiting in dogs.
- Regurgitation is passive and happens without the warning of nausea as a precursor.
- Vomiting is accomplished through active wrenching/muscle contraction, where the stomach contents are usually purged. With vomiting, before your dog actively purges the stomach, they typically shows signs of nausea with symptoms such as lip smacking, drooling, restlessness, and hard swallowing.
Treatment for Megaesophagus
The treatment for esophageal dilation in dogs is focused on treating the disease that the esophageal dilation resulted from, if possible. If the issue is not curable, the patient will have permanent esophageal dilation and is diagnosed with megaesophagus.
The use of GI motility agents and gastrointestinal protectants are a mainstay of treatment whether or not the condition is temporary or permanent. Patients with megaesophagus have a specialized feeding technique that must be done carefully and slowly. Because the esophagus cannot function normally, food and water must pass into the stomach through gravity. Therefore, the patient must be fed in a vertical, upright position with food (ideally meatballs) given slowly and very small amounts of water at a time. A Bailey Chair is commonly used, which we will discuss more below.
Patient Case: Barnaby
Meet Barnaby, 1-year-old Brussels Griffon Terrier, who presented to VERC with aspiration pneumonia. He was later diagnosed with lymphangiectasia and enteritis which led to a dilated esophagus.
Barnaby was examined by our team of specialists in the emergency, critical care, and internal medicine departments. The departments worked together and utilized the diagnostic tools, such as endoscopy, ultrasound, and radiography, to diagnose him and formulate a treatment plan. He received round-the-clock care from our dedicated veterinary nursing care team, who monitored for signs of respiratory distress, administered medications, and of course, gave him lots of tender loving care.
the Bailey chair
Barnaby was placed in what is called a Bailey Chair, a “highchair for dogs” specially designed for dogs with Barnaby’s condition to be fed upright, comfortably, and safely during the process. Barnaby was able to have a feeding tube placed during his diagnostic endoscopy procedure so we could avoid his esophagus and place food directly into his stomach by utilizing a PEG (percutaneous endoscopic gastrostomy) tube.
Everyone fell in love with Barnaby’s sweet personality and he was never without someone giving him constant love, care, and affection.
Written by: Heather Scott, Technician Learning and Development Specialist