What Causes a Dog’s Stomach to Swell?

Dr. Joe Alcorn, M.S., D.V.M.

Dr. Joe Alcorn is founder of Care Animal Hospital in Temecula, California. He has a Bachelor of Science in Biology and Doctor of Veterinary Medicine from Colorado State University. He is a member of the American Veterinary Medical Association and his advice has been featured in large publications like Bustle and Martha Steward.

Home » Blog » What Causes a Dog’s Stomach to Swell?

Have you noticed swelling or bloating in your dog’s stomach? A swollen abdomen in dogs can be a lethal emergency, or it could be caused by something simple, like overeating. One way you can make sure your dog stays in good health is by paying attention to any signs of stomach problems, so you can catch any larger issues before they advance.

At the same time, a dog’s stomach swollen and hard can be incredibly dangerous. Therefore, you should never attempt to diagnose your dog’s bloated stomach issues yourself. As soon as you notice that your dog’s stomach swollen and hard you should schedule an appointment with your chosen vet. Prompt diagnosis and treatment of abdominal problems could save your pet’s life.

Common Causes of Stomach Swelling in Dogs

There are many causes of stomach swelling in dogs. We will discuss what causes bloat in dogs, as well as ways to ease discomforts, while waiting for the vet.

Gastric Dilation and Volvulus or Bloat

One of the biggest emergencies for dogs is gastric dilation and volvulus (GDV). If left untreated, GDV can be deadly within hours. Bloat occurs when gas and food cause your dog’s stomach to stretch.

Gastric dilation and volvulus occurs when your dog’s bloated belly rotates with gas trapped inside, causing the stomach to lose blood flow.

GDV is incredibly painful, and there is no singular cause of GDV. However, it is thought to mostly be caused by swallowing excessive air and intense exercising after a meal. Other risk-factors of gastric dilation and volvulus in dogs, include:

  • Only feeding your dog one meal a day
  • Using elevated food and water bowls
  • Genetic history of bloat
  • Consuming food too fast
  • Deep-chested breeds, like Great Danes, St. Bernards, and Weimaraners. Most dogs over 99 pounds have a 20% higher risk of developing bloat.
  • Dogs between the ages 7-12 years
dog eating from a bowl

Dogs suffering from GDV often exhibit whining, having a hard time defecating, having a weak pulse, or using abnormal posture, like curling in a ball or crouching position.

If your dog is suffering from bloat, it requires prompt attention. Treating bloat may require decompressing the stomach to relieve excess gas, managing shock, and steadying the heart rate. Once your dog’s heart rate is stable, we will be able to perform surgery. If you notice that your dog has bloated stomach, your dog’s stomach feels hard, looks distended, or if she seems uncomfortable, don’t delay getting to the vet, because it could be a veterinary emergency.

As we mentioned earlier, the exact cause of bloat is not known, which can make it difficult to prevent. However, there are some things you can do to minimize the risk, including:

Peritonitis Causes Stomach Swelling

Another common condition that causes a bloated stomach in a dog is an infection called peritonitis. This is a serious infection that occurs when the dog’s stomach or intestine becomes punctured, generally due to bone splinters, tumors, ulcers, or other causes. Gallbladder and urinary bladder ruptures can also cause peritonitis.

Peritonitis is extremely painful for dogs, which can make it easier to detect than bloat. Your dog might appear reluctant to move, throw up or vomit, have a swollen stomach or appear lethargic. Emergency veterinary treatment of peritonitis is imperative since it will most likely lead to shock.

Treatment of this condition will include IV therapy, antibiotics, and medication for pain relief. We will also need to perform surgery to repair any ruptures, remove infected fluid, and flush out the abdomen.

Cushing’s Syndrome and Stomach Bloat

Does you dog have a pot belly? This could be caused by a condition called Cushing’s syndrome, which is caused by an overabundance of the cortisol hormone, also known as the “stress hormone.” Cushing’s syndrome is more common in dogs over the age of 6, and it is generally accompanied with eating, drinking, and urinating more frequently, as well as excess panting and hair loss.


Fluid can accumulate in your dog’s stomach, leading to a condition called ascites. Fluid accumulation can occur from intestinal diseases, heart failure, tumors, liver failure, or kidney disorders. Sometimes stomach swelling can occur in puppies with severe roundworm infections.

dog drinking water

Tips for Preventing Stomach Problems in Dogs

One way to prevent stomach problems in your dog is by making sure that you take her for regular vet checkups, so we can catch any lung, stomach, bowel, or heart problems before they get out of hand and lead to something more severe. You can also perform routine assessments to try to detect any symptoms of stomach problems.

When feeling your dog’s abdomen, search for lumps, heat, stickiness, swelling, or tenderness to touch. If you recognize any abnormalities in your dog’s abdomen, schedule an appointment with the vet immediately.

Are you worried that your dog might be suffering from abdominal swelling? Schedule an appointment at Care Animal Hospital in Temecula today at 951-676-4690.