Dogs can vomit for a lot of reasons, some of which are very serious while others are relatively benign. If your dog vomits only when his stomach is empty, producing just foam, mucus, and a little bile, he may have a condition known as bilious vomiting syndrome.
Veterinarians don’t know exactly what causes bilious vomiting syndrome, but they suspect it has something to do with gastric acid and other digestive juices collecting in and irritating a dog’s empty stomach. Whatever the cause, the solution is simple–feed the dog more frequently. Don’t increase the total amount of dog food you are offering, just divide it into smaller, more frequent meals. Timing these meals appropriately is also important. For example, if your dog typically vomits first thing in the morning, feed him a small meal right before bedtime.
Dogs with bilious vomiting syndrome do not appear sick in any other way. If your dog has additional symptoms such as a poor appetite, weight loss, diarrhea, or abdominal pain, make an appointment with your veterinarian. He or she can diagnose the cause, make appropriate treatment recommendations, and if necessary, prescribe anti-vomiting pet medications like Cerenia.