Overview of Canine Megaesophagus
Megaesophagus is a condition where there is decreased or absent motility (movement, muscular contractions) of the esophagus in dogs. The esophagus is the tube that carries food and water from the throat to the dog's stomach. With megaesophagus, passing food all the way to the stomach becomes difficult, and the food may be regurgitated back up into the throat. This reduced motility usually results in dilation of the esophagus.
Megaesophagus may be present at birth and become apparent shortly after weaning, or it can be acquired later in life. It can be secondary to a variety of diseases that cause neuromuscular dysfunction, or it can occur as a primary disorder for which the cause is unknown (idiopathic). It may be associated with esophageal obstruction due to a foreign object, stricture or narrowing, neoplasia (cancer), compression from adjacent masses in the chest, or compression from a vascular ring anomaly (a congenital defect of the blood vessels in front of the heart).
Affected animals may have difficulty maintaining adequate nutrition due to their inability to move food into the gastrointestinal tract. They may also develop pneumonia secondary to regurgitation and aspiration of foodstuffs into the lungs.
Megaesophagus is seen in both dogs and cats; however, it is much more common in dogs. It is hereditary in the wirehaired fox terrier and miniature schnauzer. Other breeds commonly affected include the German shepherd dog, Newfoundland, Great Dane, Irish setter, Chinese shar-pei, pug, and greyhound.
What to Watch For
Diagnosis of Megaesophagus in Dogs
A thorough description of the clinical signs is very important and can often be the key to the diagnosis. It is most important that your veterinarian understands exactly what signs your pet is exhibiting at home. Diagnostic tests are necessary to confirm a diagnosis of megaesophagus. They may include:
Treatment for Megaesophagus in Dogs
Treatment for megaesophagus is directed at the underlying disease or associated conditions. In the event no underlying cause is identified, symptomatic and supportive measures are recommended:
Home Care and Prevention for Megaesophagus in Dogs
Administer any prescribed medications and feed your dog according to the instructions given to you by your veterinarian. It is critical that you follow any special feeding instructions to reduce the risk of aspiration of food or vomitus into the lungs. It is important to maintain adequate nutrition if at all possible.
Most causes of megaesophagus cannot be prevented. However, megaesophagus associated with ingestion of certain types of foreign bodies or toxins may be prevented by closely monitoring your dog's environment.
Information In-depth for Megaesophagus in Dogs
Because the history, physical examination findings and overall presentation of animals with megaesophagus are variable, there are other illnesses that must be ruled out when establishing a definitive diagnosis. It is important to note that regurgitation, which is the effortless evacuation of fluid, mucus, and undigested food from the esophagus, is the most common clinical sign associated with megaesophagus. Regurgitation must be differentiated from vomiting, which is the forceful evacuation of digested food from the stomach.
The following are often associated with regurgitation:
Megaesophagus may occur as a component of several systemic diseases, such as:
Diagnosis In-depth of Megaesophagus in Dogs
Certain diagnostic tests must be performed to make a definitive diagnosis of megaesophagus and exclude other disease processes that may cause similar symptoms. A complete history is especially important in these cases, as regurgitation, the most common clinical sign seen with megaesophagus is often referred to as vomiting by the pet owner.
A complete diagnostic evaluation is indicated in dogs with megaesophagus since an accurate diagnosis is important for both treatment and prognosis.
Your veterinarian may recommend additional tests to exclude or diagnose other conditions, such as the following:
Therapy In-depth for Dogs with Megaesophagus
The primary goals in treating megaesophagus are to identify and treat the underlying cause, decrease the frequency of regurgitation, prevent over-distention of the esophagus, provide adequate nutrition, and treat complications such as aspiration pneumonia and esophagitis. In cases where a primary cause can be identified and treated, esophageal motility may improve with time. Treatment is symptomatic in animals in which an underlying cause cannot be identified.
Following appropriate feeding recommendations is of paramount importance, and although there is no single way that all animals should be fed, several general principals apply:
Other treatment options include:
Home Care for Megaesophagus in Dogs
Optimal treatment for your pet requires a combination of home and professional veterinary care. There is no single therapy that is recommended for all animals with megaesophagus. Each case is unique, and specific recommendations are tailored for each patient.