Gastritis in dogs is inflamation or irritation of the lining of the stomach.  Vomiting is the most common cause of gastritis.  Vomiting, in turn, is commonly caused by dogs and cats  eating things that upset the digestive tract, such as sticks, leaves, bones, or greasy foods.  Vomiting can also be caused by infection, intestinal worms, cancer, or diseases in other organs such as the kidney or liver. 

The character of the vomit can provide a hint as to the cause.  For example, sticks, bones or worms may be seen in the vomit.  Red blood indicates bleeding in the mouth, throat, or stomach, while a “coffee-ground” appearance suggests digested blood from the small intestine.  Your pet’s behavior can also provide clues.  Vomiting associated with a tense, painful abdomen, can be a sign of an intestinal obstruction, which is a serious situation that needs immediate veterinary attention.

Treatment

In mild to moderate cases of vomiting, medications are often given to calm the digestive tract or the “vomiting center” in the brain.  Your veterinarian may ask you to withhold food from your pet for a time, or to feed multiple small meals of a bland diet.  In more serious cases, intravenous fluids may be needed to correct dehydration, and any underlying problems must also be treated.  Intestinal obstructions require emergency surgery to remove the blockage.