Peritonitis

Another possible cause of stomach swelling in dogs, this serious infection is usually caused by puncture or rupture of your dog's stomach or intestine, due to splinters from a bone, ulcers, tumors, or other causes. Peritonitis can also occur if the gallbladder or urinary bladder ruptures.

Extremely painful, a dog with peritonitis may be listless, reluctant to move, have a swollen abdomen, or vomit. Shock is likely, so emergency treatment is crucial.

Treatment for peritonitis may include intravenous fluids, antibiotics, and pain relief. Surgery will also be necessary to repair the puncture, remove the infected fluids, and flush the abdomen.

Cushing's Syndrome

A dog with a pot-bellied look may have hyperadrenocorticism, or Cushing's syndrome, a condition caused by the overproduction of the hormone cortisol. More common in dogs 6 years or older, other signs of Cushing's syndrome include eating, drinking, and urinating more, as well as hair loss and increased panting.

Cushing's syndrome is usually caused by the pituitary gland overproducing a hormone; less commonly, it is due to a tumor on one of the adrenal glands. There is a newer medication that treats both forms of Cushing’s syndrome. However, surgery can be done to remove the tumor associated with the adrenal form of Cushing’s syndrome.

Ascites

Ascites is the accumulation of fluid in the abdomen, often leading to swelling. Ascites can be caused by a wide range of problems, including heart failure, liver disease, kidney problems, or severe intestinal disease. Treatment for ascites varies depending on the condition causing it.

Other Causes of Dog Stomach Swelling

Stomach swelling in dogs can also result from the dog eating too much all at once, internal bleeding due to trauma or a ruptured mass, intestinal obstruction, or tumors. Severe roundworm infection in puppies can also cause a swollen abdomen.

Tips to Prevent Stomach Problems in Your Dog

To help prevent stomach problems, be sure to take your dog in for regular checkups so that your vet can keep tabs on the health of your pet's heart, lungs, stomach, bowel, and other organs.

A quick exam of your dog's abdomen can also help you recognize some of the signs of stomach trouble. To examine your dog's stomach, feel for tenderness to touch, heat, stickiness, lumps, and of course, swelling. Take your dog to the vet right away if you notice any problems.