15 Potential Causes of Abdominal Enlargement in Dogs

Updated on May 22, 2019
alexadry profile image

Adrienne is a certified dog trainer, former veterinary assistant, and the author of "Brain Training for Dogs."

A free-ranging pregnant dog.
A free-ranging pregnant dog. | Source

Abdominal Enlargement in Dogs

The term abdominal enlargement in dogs (or abdominal distension) is used to describe the circumstance in which a dog's belly appears to bulge or be larger in certain areas. The enlargement can take place as a result of a variety of factors.

  • An accumulation of air, fat, or fluids.
  • The presence of masses or tumors.
  • Enlarged organs.

While some forms of abdominal enlargement in dogs are obvious, not all forms of abdominal enlargement are easily detected by dog owners. It takes many years of hands-on experience for veterinarians to palpate the abdomen and detect slight abnormalities such as enlarged organs.

If you notice abdominal enlargement/distention, see your vet. Your vet will likely start with a physical exam and part of that will entail palpating your dog's abdomen. Your dog's abdomen will be inspected for distention, asymmetry (one side different from the other), the presence of fluid or gas, enlargement of organs such as the spleen, liver, or kidneys, the distention of the stomach, intestines, or bladder, the presence of masses, and the enlargement of the dog's bladder or uterus.

A Look at Abdominal Organ Anatomy in Dogs

Your dog's abdomen, also less formally known as the stomach, belly, or tummy, refers to the section of the body found sandwiched in between the thorax (chest area) and the pelvis (the bony structure nearby the base of the spine to which the hind limbs attach).

Because a dog's abdomen houses various vital internal organs, the abdominal area is often referred to as an abdominal cavity. A dog's abdominal cavity contains several hollow organs of the digestive tract including the dog's stomach, small intestine, and colon (also known as large intestine).

Other organs found in the dog's abdomen include the liver, gallbladder, pancreas, spleen (located just behind the liver, in the mid abdomen), kidneys, and adrenal glands. It remains under debate whether a dog's bladder, prostate gland, uterus, and ovaries would fall under the category of abdominal organs or pelvic organs.

These vital organs are enclosed by strong abdominal muscles and protected by the vertebral column on top; some organs are also protected by the ribs.

Did You Know?

The portion of the intestinal tract known as the appendix in humans does not actually exist in dogs. Dogs, therefore, do not have an appendix and do not suffer from appendicitis.

If your puppy or dog has a swollen abdomen, see your vet to play it safe.
If your puppy or dog has a swollen abdomen, see your vet to play it safe.

15 Potential Causes of Abdominal Enlargement in Dogs

Here is a list of some potential causes of abdominal enlargement in dogs. Some of these are relatively benign conditions, while others may be suggestive of a disease process of dysfunction and are worthy of being looked at by a veterinarian. This is a limited list, and there may be several more causes not mentioned here.

1) A Matter of Weight Gain

In this case, the enlargement is due to the presence of extra fat. Weight gain is often seen in dogs who are fed caloric foods in abundance and in dogs who do not exercise enough. Dietary changes along with an exercise regimen can often help.

Certain medical conditions may cause weight gain in dogs as well. Examples include diabetes and thyroid disease.

2) Pregnancy in Female Dogs

In this case, the abdominal enlargement is due to the presence of developing puppies. Generally around week 5 or 6, the belly will start to enlarge and the mom dog will start to gain weight.

Puppies are carried in the mom dog's uterus which is found in the back half of the belly, nearby the bladder. As the puppies develop, the uterus expands. As the end of pregnancy nears, all the puppies will be quite large and the abdomen may appear enlarged near the stomach and edge of the ribcage.

Pregnancy in intact female dogs can be detected by a veterinarian via gentle palpation of the abdomen at about a month after breeding.

3) Presence of Intestinal Parasites

Dogs with heavy parasite loads may develop a potbellied appearance. Puppies are notorious for having this appearance when young. In puppies, the most common parasite known for causing a potbelly is roundworm. Fortunately, resolution of the problem is easy. After a fecal test testing positive for parasites, the vet can select the most appropriate dewormer that will kill the exact type of parasites found.

4) Enlargement of Organs

An abdominal mass may sometimes be detected by a vet upon physical examination, and this can be suggestive of liver tumors. Abdominal distension (ascites) may also be seen. An enlarged liver may also take place when a dog is in heart failure.

Normally, abdominal enlargement due to enlarged tumors won't be obvious. It often takes an experienced vet to gently palpate any enlarged organs. Sometimes, for example, an enlarged spleen is difficult to feel even for an experienced veterinarian.

5) Gastrointestinal Issues

Distension of the abdomen after eating (postprandial) may be due to gastric retention disorders, explains Dr. Jennifer E. Stokes a board-certified veterinarian specializing in internal medicine.

What may cause such retention? The presence of a tumor may be slowing down the normal emptying of the stomach leading to gas building up in the stomach. Perhaps, the nerves of the dog's intestinal tract are not working as the should.

Other possible GI issues causing a swollen abdomen in dogs include organ torsion (stomach, spleen, intestinal tract), infection of the membrane lining the cavity of the abdomen (peritonitis), foreign body obstruction, and abdominal organ trauma.

Sometimes, eating certain foods may cause a bout of pancreatitis in dogs. Pancreatitis is the inflammation of the pancreas, which may cause a dog's stomach to hurt and become hard or distended. A distended belly can sometimes also form from a lot of gas forming due to a bout of colitis.

6) A Case of Ascites

Sometimes, a dog's abdomen is enlarged when there are fluids accumulating inside the abdominal cavity. Gently pressing on the abdomen may generate at times a "wave" that looks like fluid. The fluids may accumulate as a result of malfunctioning organs such as the heart (as it happens with congestive heart failure, especially in dogs with a history of a heart murmur) or liver.

7) Presence of Blood

Blood may flow within the abdominal cavity as a complication from surgery, underlying bleeding disorders, exposure to rat poison, bleeding masses and penetrating trauma to the abdomen causing direct injury to abdominal organs (car accident, dog bite).

8) A Urinary Problem

When a dog's bladder ruptures, it may fill the abdomen with urine as a result of significant trauma such as being hit by a car. Another possible cause of abdominal/pelvic swelling includes a urinary blockage.

9) Intestinal Lymphoma

Lymphoma is a type of cancer capable of attacking almost any system. In the case of intestinal lymphoma, this cancer will block the lymphatic system leading to leaking of fluids into the abdomen. This type of cancer may be detected on ultrasound where enlarged lymph nodes may be seen.

10) Presence of Masses

Several types of cancer may affect the organs found in the dog's abdomen and superficial masses may be found too. Sometimes benign or malignant skin masses may cause localized enlargement of certain areas of the abdomen.

Lipomas are benign masses often found just under the skin and are usually movable. They are often found in the dog's abdominal area. A fine needle aspiration can help determine where a skin mass on the abdomen is cancerous or not. Generally, these benign growths are only removed if they are interfering with a dog's ability to walk/move.

11) Cancer of the Spleen

Spleen cancer in dogs (hemangiosarcoma) may produce acute swelling of the abdomen, abdominal pain, labored breathing pale gums along with a distended abdomen. The swelling of the abdomen takes place when the spleen ruptures causing blood to fill up space in the abdomen. The tricky part about these tumors is that you often can't know whether they're benign or cancerous until the vet removes the entire spleen and has a pathologist look at it.

When spleen cancers enlarge, they may sometimes put pressure on the dog's stomach and intestines, causing discomfort and lack of appetite.

12) Presence of Air

When a dog's abdomen fills with air, it may lead to a life threatening complication known as GDV. Deep-chested dogs are typically predisposed to this condition. The stomach basically fills up with air and twists on itself cutting blood supply and causing shock.

GDV typically causes dogs to make frequent attempts to vomit, assume a hunched-up posture, become restless, and their stomach becomes distended and tight like a drum causing a thumping sound when patted with fingers. If you suspect bloat in your dog, please see an emergency vet at once.

13) Low Thyroid Levels

When the dog's thyroid gland becomes sluggish and stops producing sufficient amounts of thyroid hormones, affected dogs may start gaining weight. Other symptoms include bilateral hair loss, dry coat or seborrhea. Skin and hair problems are usually first seen by the tail area, base of the ears and lateral lumbar regions.

14) A Case of Excess Cortisol

Cushing's disease takes place when the dog's cortisol levels are too high. This condition requires specific testing that is not routinely carried out: a dexamethasone suppression and/or ACTH stimulation test.

Affected dogs (a good 90 to 95 percent) tend to gradually develop a potbellied or pendulous appearance of their abdomen. This potbelly is believed to be the result of increased weight of abdominal contents due to redistribution of fat from various storage areas to the abdomen along with a decrease in muscle strength (muscle wasting). The increased size and weight of the liver as a result of excess cortisol may also play a role in the pot-bellied appearance.

On top of a pot-bellied appearance, dogs with Cushings may develop increased drinking, increased urination, panting and a dull coat.

15) A Uterine Infection

A uterine infection, medically known as pyometra, affects only intact female dogs (not spayed). This is a life threatening condition. An intact female dog acting sick, showing decreased appetite and displaying an enlarged abdomen/pelvic area may be suffering from a distended uterus. See your vet at once to play it safe.


This article is not meant to be used as a substitute for professional veterinary advice. If your dog has an enlarged abdomen and/or is acting sick, please consult with a vet at your earliest convenience.


  • Textbook of Veterinary Internal Medicine Expert Consult: Expert Consult, ... 7e(2 Volume Set) by Stephen J. Ettinger DVM DACVIM
  • Withrow and MacEwen's Small Animal Clinical Oncology - 5th Edition
  • VCA Animal Hospitals, Testing for Abdominal Enlargement in Dogs
  • Author's own experience as a former veterinary assistant for AAHA-accredited animal hospitals.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2018 Adrienne Farricelli


    0 of 8192 characters used
    Post Comment
    • alexadry profile imageAUTHOR

      Adrienne Farricelli 

      11 months ago

      Cricket, thanks for stopping back. If your sick dog brought you to this page on abdominal enlargement in dogs, I hope with the help of your vet that you're able to pinpoint the problem and that your dog makes a speedy recovery!

    • profile image

      Cricket K. 

      11 months ago

      Hi, thanks so much for this for the time you took to research and compile. This was a great help in answering my questions.

    • Suhail and my dog profile image

      Suhail Zubaid aka Clark Kent 

      2 years ago from Mississauga, ON

      Hi Adrienne,

      This was a very medically inclined article that I found informative. I know a Labrador, a friend of our K2, died due to abdominal enlargement caused by some disease that I was not able to find from the neighbour.


    • clivewilliams profile image

      Clive Williams 

      2 years ago from Jamaica

      Good Listing here.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, pethelpful.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://maven.io/company/pages/privacy

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)