Canine Achalasia Study

We are currently seeking tissue samples from dogs diagnosed with megaesophagus.

Purpose of the Study

This study aims to describe the histopathologic features of the gastroesophageal sphincter in dogs with megaesophagus due to any cause.

It has been proposed that some dogs with megaesophagus may have a form of disease called esophageal achalasia, a condition described in people.  Esophageal achalasia is characterized by failure of the gastroesophageal sphincter to relax and subsequent impairment of the esophagus to propel food material into the stomach. Over time the esophagus dilates and becomes dysfunctional due to accumulation of food material within it.  In people, esophageal achalasia typically results from inflammatory damage to the muscle or nerves of the gastroesophageal sphincter but can also be congenital.  This damage can often be seen on biopsies of the gastroesophageal sphincter.  No veterinary studies have been done to determine if dogs with megaesophagus also have changes or damage to the gastroesophageal sphincter which could be contributing to their development of megaesophagus.     

Dr. Jillian Haines and Cake

Message to Owners

As many of you have experienced, megaesophagus is a challenging disease to treat. Despite all of our best efforts to fight this disease, some of our pets will still succumb to the disease or other related conditions. For now, no cure for megaesophagus exists and we continue to work on improving our knowledge and understanding of this disease. Unfortunately, sometimes the best methods for obtaining this information are much too invasive to perform on our beloved pets. That often means that we can only get our answers after they have passed away. An autopsy, often called a necropsy in veterinary medicine, is a common procedure done in both people and animals to determine the cause of death but also to collect tissue samples that can be used as part of research projects to further our understanding of a disease.

It is for these reasons that I am asking you to consider a tissue donation from your dog with megaesophagus if they do unfortunately pass away. The cause of death does not have to be directly related to the megaesophagus and you can work with your family veterinarian to decide if and how you would like the tissues collected. A full necropsy is not required in order to obtain samples of the esophagus and gastroesophageal sphincter. If you wish to have these samples collected, you will need to let your veterinarian know before or immediately after your dog passes as they need to be collected rapidly and preserved.

Thank you so much for considering this contribution towards our research into the causes of megaesophagus in dogs. Our dream for every dog with megaesophagus is for them to live a full and happy life and we hope that research like this will continue to lead us closer to that dream.


Jillian Haines, DVM, MS, DACVIM

Associate Professor, Small Animal Internal Medicine