Vomiting is a common clinical sign in dogs. It can be associated with many disorders. Chronic vomiting may occur when the stomach is constantly inflamed and irritated (gastritis). This irritation usually leads to chronic and episodic vomiting that may occur over a period of weeks or months. Chronic gastritis is usually not associated with eating, and it may or may not be concurrent with appetite loss, weight loss or abdominal pain.
Vomiting of yellowish, bile-stained fluid or foam early in the morning, or whenever the stomach is empty, can be due to a form of chronic gastritis called "reflux gastritis". This disorder occurs when the stomach lining is injured because of chronic "back flush" or "reflux" of duodenal contents, such as bile and pancreatic enzymes. Dogs that have reflux gastritis tend to be healthy otherwise and generally don't vomit any other times.
Diagnosis of chronic reflux gastritis or any other kind of gastritis usually requires a biopsy of the lining of the dog's stomach. Some veterinarians will try symptomatic treatment first to see if the problem can be resolved without resorting to surgical or endoscopic diagnostic methods.
Reflux gastritis can often be corrected by simply feeding your pet several small meals throughout the day or by feeding a late bedtime meal. Feeding helps neutralize the dog's refluxed duodenal contents. There are also drugs available that can help. Your dog's veterinarian can help resolve this problem with a treatment specifically tailored to your dog's needs.