It is not unusual for dogs, especially puppies and younger dogs, to vomit a foamy, yellowish or dark green liquid, especially in the morning. This substance is most likely bile, a digestive fluid produced in the liver. Although vomiting is the most common reason that people take their dogs to the vet, occasional vomiting is normal and usually not a cause for concern. Pups and young canines are especially prone to it because their youthful digestive systems are rather delicate.
In the case of puppies, morning vomiting is likely due to excess acid that accumulates overnight in an empty stomach because of an overactive digestive system. Otherwise, the most common cause of vomiting in dogs is gastritis, which is irritation of the stomach lining. Gastritis can be either acute or chronic. Acute gastritis comes on suddenly; it's basically what's commonly referred to as "food poisoning" in humans, and usually passes in a day or two. Chronic gastritis can occur when your dog has swallowed something indigestible, such as plastic, or from certain drugs such as aspirin, or the ingestion of household chemicals.
The best way to judge whether vomiting indicates a serious underlying condition is to assess your dog's overall health. A dull coat, lethargy, and weight loss are indications that your dog should see the vet. Excessive sleeping and loss of interest in usual activities, such as going for walks and playing, are also clues. Weight loss and loss of appetite are other symptoms that merit professional attention.
For puppies, a dog biscuit or any other treat before bedtime can settle the stomach and prevent the acidity that causes vomiting. Also, you may try altering your dog's diet to a bland, high-carbohydrate food (Webmd.com suggests Hills Prescription Diet i/d). Or, you make a homemade version by mixing boiled rice with cottage cheese.
Playing It Safe
Of course, if the problem persists, have a vet examine your dog. He may prescribe medication to calm the animal's stomach, such as an acid blocker like Pepcid or Tagamet. Chronic gastritis is usually diagnosed by a gastroscopy of the stomach. Other courses of treatment may include corticosteroids and a hypoallergenic diet. Blood tests will reveal kidney problems, and lab analysis of stool samples can rule out parasites.
Vomiting bile is something most young dogs will outgrow and that others will overcome with a change in diet. For dogs that suffer from a short term bout of vomiting (one or two days), the outlook is positive. If there is a serious disorder, however, prompt medical attention will minimise the long-term damage. If your pet seems lively, healthy and happy, and vomits only occasionally or once in the morning, try the measures above before seeing the vet. However, if your dog is vomiting chronically and seems lethargic or ill, it is wise to have him examined by a veterinarian as soon as possible.