Bilious Vomiting Syndrome

Dear Dr. Jody:  Our three year old female Bichon Frise, "Christie", has recently developed some tummy upset.  Almost every morning she will vomit up some yellow foamy liquid.  It hasn't affected her appetite at all, and she isn't sick in any other way.  What could be making her so nauseous?

What a frustrating situation!  Certainly there are dozens of conditions that can lead to vomiting, and your veterinarian will need to perform a thorough physical examination and run basic lab tests prior to arriving at a diagnosis.  However, Bichons are very prone to a condition known as Bilious Vomiting Syndrome, and it is possible that Christie is experiencing symptoms related to BVS.

BVS results when an irritating substance called bile ends up where it doesn't belong.  Bile, a fluid rich in digestive enzymes, is produced by the liver and then shunted to the gallbladder for storage.  When the gallbladder contracts in response to a recently eaten meal, the bile travels down a little duct and is discharged into the upper small intestine.  Here it becomes a critical component in the digestion of fats and carbohydrates.  A normal healthy digestive tract is constantly on the move.  Through waves of peristalsis, the stomach pumps liquefied food into the small intestine where bile is ready and waiting to assist in digestion.  In some patients, there is a condition of hypomotility, meaning the stomach isn't pumping food to the small intestine as effectively as it should.  If the stomach is a little on the lazy side, bile that accumulates in the upper small intestine can leak back upstream into the stomach.

The stomach has a lining that is specially designed to safeguard against erosion by gastric acid, whose pH is in the highly acidic range of 1-2.  However, because the pH of bile is much higher, in the range of 8-9, this very alkaline fluid can be very irritating to the lining of the stomach.

In patients who suffer from BVS, bile is leaking from the intestine into the stomach when the stomach is at its most inactive state.  In most cases, this occurs early in the morning when the stomach hasn't had anything to do all night and is completely empty.  The stomach responds to this insult of alkaline fluid by vomiting it up.

Dogs who suffer from BVS often find relief from this annoying symptom if offered a small late-night meal.  If you withhold about 10-20% of your dog's daily food ration throughout the day and then offer it as a bedtime snack, you may find your pet's early morning nausea is relieved.  In some cases, your veterinarian may determine that your pet may benefit from medication.  Helpful medications include prokinetic agents to improve gastric motility, and H2 blockers to help protect the lining of your dog's stomach.

BVS can be fairly straightforward to treat.  If you suspect your dog has a chronically upset stomach, regardless of the possible cause, please consult your veterinarian.  Daily nausea is a miserable affliction!