Gastroesophageal Reflux in Dogs
Gastroesophageal reflux is a condition characterized by the uncontrollable reverse flow of gastric or intestinal fluids into the tube connecting the throat and the stomach (esophagus). This may be due to a brief relaxation of the muscular opening at the base of the esophagus (referred to as the sphincter), as well as chronic vomiting. Gastroesophageal reflux is fairly common in dogs, and may occur at any age, although younger dogs are at greater risk.
The gastric stomach acid, pepsin, bile salts, and other components of the gastrointestinal juices cause damage to the protective mucus lining the esophagus. This can result in inflammation of the esophagus (esophagitis).
The condition or disease described in this medical article can affect both dogs and cats. If you would like to learn more about how this disease affects cats, please visit this page in the PetMD health library.
Symptoms and Types
Gastroesophageal reflux can cause esophagitis with varying amounts of damage. Mild esophagitis is limited to a mild inflammation of the esophageal lining, while more severe ulcerative esophagitis causes damage to the deeper layers of the esophagus.
The dog’s behavioral history can reveal symptoms such as spitting up (regurgitation) of food, evidence of pain (whining or howling, for example) while swallowing, lack of appetite, and weight loss. A physical exam will often not reveal any concrete findings. Severe esophagitis may include symptoms of fever and extreme salivation.
Causes
Gastroesophageal reflux may occur when an anesthetic is administered, causing the opening between the stomach and the esophagus (gastroesophageal sphincter) to relax. Improper positioning of the patient during anesthesia, as well as a failure to fast the dog properly prior to anesthesia, can result in gastroesophageal reflux.
An associated condition is a congenital (present at birth) hiatal hernia, which is suspected of heightening the risk for gastroesophageal reflux.
Young dogs are at greater risk of developing this condition because their gastroesophageal sphincters are still developing. Long-term or chronic vomiting is another risk factor.
Diagnosis
The best means of diagnosis is generally an esophagoscopy, an examination which uses an internal camera to view the lining of the esophagus. This is the most effective way to determine if changes in the mucus of the esophagus are consistent with esophagitis due to gastroesophageal reflux. The examination may also reveal an irregular surface in the mucus lining, or active bleeding in the esophagus.
Alternative diagnoses include ingestion of a caustic agent, a foreign body or tumor in the esophagus, a hernia in the upper portion of the stomach (hiatal hernia), disease of the throat or mouth, or a condition in dogs where the muscles of the esophagus do not function properly in pushing food into the stomach (megaesophagus).
Treatment
Most treatment is done at home, by withholding food for one to two days, and thereafter following a dietary regimen of low-fat, low-protein meals given in small, frequent feedings. Dietary fat and protein should be limited, as fat decreases the strength of the muscle between the stomach and esophagus, while protein stimulates the secretion of gastric acid.
Medications are an additional option. Drugs known as gastrointestinal pro-kinetic agents improve the movement of stomach contents through the intestines and also strengthens the gastroesophageal sphincter. Regardless of any medications, a change in diet is advisable.
Living and Management
After initial treatment and alteration of diet, it is advisable to continue monitoring for gastroesophageal reflux. Watch for signs of discomfort. A continued low-fat, low-protein diet will prevent future incidences, and high-fat foods should be avoided, as they may worsen gastroesophageal reflux.
If the dog does not respond to initial medical treatments, a follow-up esophagoscopy may be advised.
Prevention
High-fat foods can worsen acid reflux. The best prevention is a healthy diet that is low in fatty foods.