6 Causes Of Distended Bellies In Dogs

distended bellies in dogs

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With age, their body tends to droop down but distended bellies should never be taken for granted. That’s because a swollen belly can mean anything from little indigestion to something fatal like bloat or ascites.

So, here are 6 causes of distended bellies in dogs.

6 Causes of Distended Bellies in Dogs

There are many reasons for your dog to get a distended stomach. In this article, we list the 6 most dangerous causes along with their symptoms.


Gastric Dilation and Volvulus (GDV) or Bloat is one of the most common reasons for a sudden distended stomach, it can turn deadly any moment. A dog’s anatomy is very different from that of a human.

bloat in dogs
Source: petcoach.co

The diagram shows the anatomy of a dog. Their stomach has to work against gravity to digest food. Bloat usually happens after a dog has eaten a lot of food at once. During digestion, the stomach releases a lot of acids or gastric juices.

If they have a heavy meal the stomach has to produce more gastric juices to digest the food. This is when the juices sometimes exceed the stomach capacity and form a huge balloon (dilation). The air in the stomach makes it lighter than the other organs. This causes the stomach to float, twist (volvulus) and entangle with the other organs.

Sometimes, when dogs get bloat, the stomach entangles with a very important vein called the caudal venae cava. This vein takes deoxygenated blood back to the heart. When the stomach is twisted around the caudal venae cava there is a blockage of bad blood.

Bloat is very painful and it can go very bad, very fast. It usually happens after a heavy meal. Visible signs of bloat are sluggishness and if the stomach has twisted, your dog may undergo a complete shock.

If your dog starts to show signs of bloat, you should rush them to the hospital. Seconds matter in moments like these. It can save your dog’s life. 

Once your doctor confirms that your dog has bloat, they will usually deflate the stomach by removing the gas with a large needle. In the worst cases, dogs have to undergo surgery to re-position the stomach.

Your dog is more likely to have bloat if they are:

  • 7 years or older
  • Has had bloat once before
  • Has one heavy meal in a day
  • Runs or plays excessively after a meal
  • Some breeds like Great Danes are predisposed to bloat
  • Common in large breeds
  • Common amongst deep-chested dogs

2. Round Worm Infection

Roundworms are the most common kinds of worms that affect dogs. They are very sturdy and can survive in most parts of the dog’s body. But they thrive in the dogs gut. Most adult dogs don’t show symptoms of roundworms but pregnant mothers can pass it onto their babies.

Puppies don’t have a high tolerance for roundworms and they are the ones most affected by these intestinal parasites. Adults can be affected by roundworms too and the density of the worms matter greatly in the effects and symptoms of the condition. A 100 sexually mature adult worms are enough to make a puppy really sick.

The most common symptom is, of course, a distended belly. But, with roundworm infections, you may see other symptoms too like hair fall, lethargy, loss of appetite or irregular appetite. Sometimes you may see mucus and worms in their poop and vomit. In severe cases, it may also lead to death.

The best way to prevent roundworm infection is by conducting deworming on time. Puppies as small as three months cannot take strong deworming medicine. Hence, they need to be dewormed once every two weeks.

This medication is strong enough to kill the mature parasites but not the larvae and eggs. Within the next few weeks, the larvae become mature, that’s when they have their second dose of medication and ultimately they have medication to kill the final lot of worms that have hatched from eggs and have matured in their body.

Adult dogs need to be dewormed once every 3 – 4 months. However, there is no harm in deworming them once a month if you are living in a place prone to roundworm infections.

Remember that rounds can affect both dogs and humans, especially infants. Hence, it is in our best interest to deworm them on time.

3. Cushing’s Disease

Cushing’s disease is becoming more common among dogs because of poor diet and lifestyle. The best way to explain Cushing’s disease is that it causes an excess of cortisol hormone. Cortisol secrets when your body is under stress.

It’s normal for a body to be under stress for a short period of time but if they are stressed for months on end, it may cause many other health issues.

Common symptoms of Cushing’s Disease include:

  • A distended belly
  • Thinning hair
  • Increase in appetite
  • Lethargy

With Cushing’s disease, you may see a slow progression of the size of the belly. Nevertheless, you need to take it seriously and take them to the vet as soon as you can.

There are many treatments for the Cushing’s Disease, both most medications have strong side effects, hence your dog may encourage you for a lifestyle change. This includes a proper healthy diet and exercise.

4. Pyometra

Pyometra is a very serious condition that happens to female dogs that have not been spayed. It is a  severe infection that occurs within the uterine lining and is very painful for them.

When the female dog does not get pregnant the uterine lining tends to build with age. This is why there is a 20% chance for a dog to get pyometra when they are about 10 years old. Hormonal treatments to prevent menstruation and/or pregnancy can also lead to pyometra as well.

There are two types of pyometra – open pyometra and closed pyometra. In the open pyometra, the cervix is open and hence the puss is discharged from the vagina. Though most dogs are clean, many pet owners say that the vaginal discharge was the first pyometra symptom they detected.

In the case of closed pyometra, there is no cervical opening and hence it’s harder to detect the disease and it can get very dangerous for the dog because the puss has nowhere to go. It usually builds inside the uterus and causes it to swell up overnight.

Common symptoms of pyometra include:

  • A distended belly
  • Puss discharge from the vagina
  • Lethargy
  • Difficulty walking, climbing and moving

Just like bloat, pyometra can become bad very fast. In severe cases, doctors will conduct a complete hysterectomy to remove the uterus and ovaries. In milder cases, there are antibiotics to cure pyometra but there is a 5% fatality rate with treatment.

Surgery not only ensures that your dog is cured, but it also makes sure they never get pyometra again. 

5. Ascites

Ascites is a broad term that refers to fluid retention in the abdomen. A number of problems can lead to ascites. This is why it’s hard to determine symptoms and treatment for the condition. The most common undeniable symptom of Ascites is a swollen belly. It may happen within minutes and some dogs may refuse to eat.

ascites in dogs
Source: todaysveterinarypractice.com

As the image above suggests, ascites can lead to severe swelling and it can deteriorate very quickly. Hence they must be rushed to the hospital before there is a rupture or their body goes into shock.

Dogs prone to ascites are those with heart, liver or kidney problems. Malnourished dogs with a low protein count may also get ascites

6. Peritonitis

The peritoneum is a thin mucus lining that separates the abdominal cavity and the external fat under the skin. Sometimes the peritoneum can get inflamed because of internal injury. This leads to peritonitis.

peritonial lining diagram
source: pintrest.com

Peritonitis can be a result of external injuries or because of disease that leads to internal injury.  Diseases like liver, kidney and heart disease, ruptured gall bladder, bile duct or bladder, perforated colon etc can cause peritonitis. 

Either way, peritonitis is a serious condition that can become severe very fast. It needs to be given emergency care and your dog must be rushed to the hospital.

Symptoms of Peritonitis Include:

  • Sudden swelling in the abdomen
  • Vomiting
  • Diarrhoea
  • Lethargy
  • Canine Anorexia
  • Palpitations

Other reasons for distended bellies in dogs include obesity and an unplanned pregnancy. These are of course less worrisome reasons but need to be addressed as soon as possible.

If your dog has a swollen belly, you must take them to the vet as soon as you detect it. It can be an unplanned pregnancy or a life-threatening illness and you should never take your chances.

In most cases, your doctor will conduct an ultrasound or an x-ray to determine what is wrong. A few doctors may recommend a blood test however, in most cases, blood tests can only give doctors a vague idea as to what’s wrong.

Lastly, a swollen abdomen is very painful for a dog, hence they may isolate themselves or get severely agitated when you come near them. Please take all the precautions you need to take them to the vet. Resistance can make the condition worse.

We hope you are able to use this article to help your dogs on time. Has your dog ever had a distended belly? Tell us all about it in the comments section below!

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About Dheepakh

About Dheepakh

Dheepakh is a dedicated pet parent. His love for his dogs turned him into a pet food enthusiast. He has dedicated all his life to understand pet food nutrition and is eager to learn everyday.

One Reply to “6 Causes Of Distended Bellies In Dogs”

  1. Dravin

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