Dear Daisy Dog: Our golden retriever Clyde was spitting up, so we took him to the veterinarian who diagnosed megaesophagus. The vet is doing more tests but for now is having us feed him on the stairs and then stand him up on his hind legs for 10 minutes after he eats. I know the name means “large esophagus,” but I’d appreciate more information about this disease.

Daisy Responds: The esophagus is the muscular tube connecting the mouth to the stomach. When the esophageal muscles are too weak to propel food to the stomach, food sits in the dilated, flaccid esophagus and may return to the mouth, where it’s spit out. This passive process, called regurgitation, is the most common sign of megaesophagus.

Regurgitation is very different from vomiting, an active process that involves retching and abdominal contractions. Vomited food is brought up from the stomach and duodenum, the first segment of the intestines.

Megaesophagus can be a primary disease or it may occur secondary to another condition, such as myasthenia gravis, Addison’s disease (hypoadrenocorticism) or hypothyroidism. If your veterinarian’s testing identifies an underlying disorder, treating it should help.

Nevertheless, management of megaesophagus includes feeding Clyde in a vertical position, with his spine perpendicular to the floor, and maintaining that posture for 10 to 30 minutes after the meal, so gravity helps move food to the stomach.

Many families make or purchase a Bailey chair to keep the dog comfortably upright. See http://groups.yahoo.com/group/megaesophagus/ for a photo and to join the canine megaesophagus support group.

Small, frequent meals usually help. Your veterinarian may have you experiment with different kinds and consistencies of food to determine what works best for Clyde.

Any food that gets inhaled into the lungs can cause aspiration pneumonia, a life-threatening condition. Call your veterinarian immediately if Clyde develops lethargy, breathing changes, coughing or other difficulties.