Canine Megaesophagus

What Is Canine Megaesophagus?

 http://www.caninemegaesophagus.org/

• Megaesophagus is difficult to detect and diagnose, and the medical options are few. But, many of these pets can be managed and lead relatively normal lives. The condition is reported in humans, dogs, cats, ferrets and other animals. (For simplicity sake we will use the dog as the typical patient in discussions on this site.)
• The muscles of the esophagus fail and it cannot propel food or water into the stomach. (Its like a balloon that has been inflated several times and then hangs limp.)
• The result is that ingested food sits in the esophagus within the chest cavity and never makes it to the stomach.
• The most serious complication is that digestive fluid/food will at some point pool in the esophagus which generally results in aspiration of digestive fluid/food, leading to pneumonia. (Aspiration Pneumonia)
• Megaesophagus can occur at any age as a puppy, or as an older dog. If it afflicts a puppy, the cause is usually genetic, or can be due to a surgically repairable condition called PRAA (Persistant Right Aortic Arch). If not secondary to another disorder in adult animals, it is called "idiopathic" (cause unknown).
• Megaesophagus can be secondary to other diseases such as Myasthenia Gravis, Thyroid, Addisons and other Neurological disorders.

• Regurgitation of water, mucous or food. (Regurgitation is throwing up without any warning; "vomiting" is associated with retching.)
• Loss of appetite or refusal to eat.
• Sudden weight loss.
• Swallowing difficulty, exaggerated and/or frequent swallowing.
• They will also try to clear their throat frequently with a "hacking" sound.
• Sour and/or foul smelling breath.
• Many canines may be mis-diagnosed with a gastro-intestinal problem.
• Aspiration pneumonia is a frequent complication.

• Your canine needs to be placed in a vertical feeding position immediately to avoid starvation and/or aspiration pneumonia. (Note: Not an "elevated bowl." Elevating the bowl does not place the esophagus in the proper orientation so that gravity will work.)
• Vertical feeding can be accomplished with the Bailey Chair. (http://www.youtube.com/watch?v=BQF19LR1rRk)
• The canine must remain in the chair for 20-30 minutes post feeding to allow gravity to work.
• A low-fat or low residue canned food fed either in a milkshake consistency or in "meatballs" works best. (If using the meatball method, they must be swallowed whole.) Each dog is different and experimentation with food consistency is required.
• Multiple feedings, 3-4 meals per day, is also suggested.
• Fluids must be consumed in the vertical position as well.
• Medications may include an acid reducer (like Pepcid-AD or Prilosec) 1 or 2 times per day; motility drugs (metoclopromide/reglan, cisapride/propulsid/, low dose erythromycin) to help empty the stomach to minimize reflux from the stomach into the esophagus; and/or an esophageal "bandage" for esophagitis, (carafate/sucralfate). Antibiotics for aspiration pneumonia, or for antibiotic responsive gastroenteritis may also be required.

Information below is taken from: Atlantic Veterinary College (AVC) at the University of Prince Edward Island.

With this condition, there is dilation of the esophagus due to a loss of normal peristaltic function. Peristalsis is the process by which waves of muscular contraction move along the contents (food in this case) of tubular organs. Animals with megaesophagus regurgitate undigested food shortly after eating.

Dogs may be born with canine megaesophagus or they may develop it later in life. It is commonly seen with other disorders such as myasthenia gravis   and peripheral neuropathies

How Is Megaesophagus Inherited?

This is an autosomal recessive trait in the wire-haired fox terrier, and autosomal dominant in the miniature schnauzer. The mode of inheritance has not been determined for other breeds that are predisposed to this condition.

What Breeds Are Affected by Megaesophagus?

Chinese shar pei, German shepherd, Great Dane, greyhound, Irish setter, miniature schnauzer, wire-haired fox terrier.

For many breeds and many disorders, the studies to determine the mode of inheritance or the frequency in the breed have not been carried out, or are inconclusive. We have listed breeds for which there is a consensus among those investigating in this field and among veterinary practitioners, that the condition is significant in this breed.

What Does Megaesophagus Mean to Your Dog and You?

Although it may not be noticed until young adulthood, this disorder is usually first recognized in puppies around the time of weaning. Affected pups regurgitate food, fail to thrive, and may develop respiratory difficulties associated with aspiration pneumonia due to inhalation of food particles. Signs include laboured breathing, fever and lethargy, and nasal discharge.

Some dogs appear to gradually outgrow this condition (by a year or so), while in others there is no improvement.

How Is Megaesophagus Diagnosed?

Regurgitation of undigested food shortly after eating is the main sign with this disorder. Your veterinarian will take chest x-rays to determine if your dog has megaesophagus, and perform other laboratory tests since there are several conditions that may be associated with this disorder. 

For the veterinarian: Since megaesophagus may be associated with many different conditions,  the diagnostic work-up should include CBC, biochemical profile, urinalysis and survey thoracic radiographs in all cases.

How Is Megaesophagus Treated?

If an underlying cause can be identified, treatment may improve esophageal function. There is no specific treatment for the megaesophagus itself, but it can usually be managed by feeding small, frequent, high-caloric meals from an elevated location so that gravity assists the passage of food. Different consistencies of foods can be tried to determine which causes the least regurgitation.

Some dogs appear to outgrow the problem, while in others there is no improvement and feeding management is required for life. Your veterinarian will discuss with you possible complications that you must watch out for, the most serious of which is aspiration pneumonia.

Breeding Advice

Affected wire-haired fox terriers, their parents (carriers of the trait) and siblings (suspect carriers) should not be bred. Affected miniature schnauzers should not be bred.

In other breeds in which inheritance is unknown, it is safest to avoid breeding affected dogs, their parents and siblings.