Why Does My Dog Have a Swollen Stomach?

Dr. Benjamin Harries

Aug 17, 2021

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A swollen stomach is not something to be taken lightly when it comes to your dog. Most times, it’s an indication of a serious health issue. While a reason why your dog’s stomach is swollen may be due to overeating, it is more likely that your dog is needing emergency medical attention. There is, of course, a difference between your pup gradually gaining weight around their belly due to overeating and lack of exercise versus truly being bloated.

When is a Swollen Stomach Dangerous for Dogs?

For the condition to truly be bloat and not weight gain, your dog’s stomach will be swollen and hard or have an unusual shape. If you notice this, call your veterinarian immediately. If it’s after hours, you should take him to the emergency vet. Bloat generally occurs when food or gas stretches the dog’s stomach.

Some reasons for bloat can be fatal if left untreated.

Reasons Why Dogs Get Swollen Stomachs

There are a number of reasons why a dog can get a swollen abdomen, and some are more serious than others.

Below are some potential reasons why your dog has a swollen stomach:

Gastric Dilation Volvulus (GDV)

One of the most dangerous and most common reasons for your dog’s stomach to be swollen is gastric dilation volvulus, or GDV for short. This particular disease can have detrimental effects or even kill your pup within hours.

It occurs when the dog’s distended stomach rotates, which traps the gas inside and blocks off the stomach’s blood supply. It’s terribly painful and there isn’t really one cause to pinpoint. It has been linked to swallowing air and intense exercise after a meal.

Additional Risk Factors of GDV

There are some additional risk factors to take note of when it comes to GDV. If you only feed your dog once a day, use elevated bowls, consume dry food, or eat too quickly, then they are at a higher risk. Some other additional risk factors include having a family history of bloat or are of a certain breed.

Deep chested breeds like St. Bernards and Great Danes are more likely to experience GDV. In fact, most dogs that weigh over 99 pounds have a 20% higher risk of the disease.

Finally, older dogs between 7 and 12 years of age are at risk.

Treatment for GDV

Treatment of GDV cannot be done by you alone. You absolutely have to take your dog into a vet as quickly as possible. Along with the swollen stomach, you may notice your dog is whining, having difficulty defecating, sitting or laying in an abnormal position as if they’re uncomfortable, or having a weak pulse.

Treatment generally includes removing excess gas from the stomach, stabilizing the heart rate, and managing shock. The vet can go in for surgery as soon as your dog is more stable.

Preventing GDV

Preventing GDV is difficult since there isn’t just one known cause to the disease. It is recommended that you feed your dog twice or more daily rather than once and incorporate canned food into the mix. It’s also important to allow your dog to rest and digest after eating rather than exercising on a full stomach.

There is also a preventative measure surgical procedure called a gastropexy that you may speak to your vet about if your dog is a predisposed breed. This can be done at a younger age as well. 


Another condition that can cause your dog’s stomach to swell is peritonitis. It’s quite serious because it occurs when the dog’s stomach or intestines have ruptured.

Usually this happens because of ulcers, tumors, or bone splinters. Urinary bladder or gallbladder ruptures can also cause peritonitis. This condition is extremely painful so you will notice bloat and your dog may be unwilling to move.

If your dog has this condition, it’s very easy for your dog to go into shock, so make sure to get him straight to a vet for treatment. The vet will need to repair the puncture, remove infected fluids, and flush out the abdomen. The sooner he is taken to the vet, the better.

Cushing’s Syndrome

A third common cause of stomach swelling in dogs is hyperadrenocorticism, or Cushing’s syndrome. If your dog has Cushing’s, he will have a pot-bellied look along with increased hunger, thirst, and urination. Some dogs will also start to lose hair or show an increase in panting.

The cause of Cushing’s is usually the pituitary gland overproducing a hormone, but it can also be due to a tumor in an adrenal gland. If the reason is a tumor, it can be removed via surgery. There is also medication that can be taken to treat Cushing’s.


Ascites is another reason your dog’s stomach may appear swollen. It’s the accumulation of fluid in the abdomen, which in turn, causes swelling. There are many reasons why your dog may experience ascites.

Common reasons include heart failure, liver disease, kidney disease, or intestinal diseases. Puppies can get it from various infectious diseases.

See a Vet for Your Dog’s Swollen Stomach

While there is a chance that your dog’s stomach is swollen just from eating too much, there is a greater chance that it’s something much more serious. Look for additional signs and symptoms and call your vet immediately if your pup’s stomach is swollen and hard.

Because of the nature of the above diseases and conditions, there is no time to waste. Quick action can be a matter of life and death. It’s important to regularly self-examine your four-legged friend to make sure that you don’t notice anything out of the ordinary. By staying vigilant and keeping a watchful eye, you can protect your pup from further complications.

The emergency vets at VEG are available 7 days a week to help care for your dog’s swollen stomach. At all of our VEG locations, we’ll work to get to the bottom of your dog’s condition and decide the best course of actions to help treat your pet.