Distended Abdomen in Dogs

Written By hannah hollinger
Published: 04/19/2017Updated: 11/04/2021
Veterinary reviewed by Dr. Linda Simon, MVB MRCVS
Distended Abdomen in Dogs - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Distended Abdomen?

In dogs, a swollen or distended abdomen may be a sign of a significant medical condition or disease, or it may be due to something less worrying, such as a resolvable bacterial infection or parasites. Due to the possibility of organ failure or breathing difficulty, however, any swelling in the abdominal area warrants an immediate veterinary visit. 

Some underlying causes of a distended abdomen are potentially fatal and indicate a dysfunction or disease process involving a major organ such as the heart, lungs or kidneys. Additionally, most cases of abdominal distension cause pain and discomfort that may be alleviated with treatment. 

One probable cause of abdominal distension in dogs is a condition called ascites (or abdominal effusion), which is a general term that refers to the build-up of fluid in a dog’s abdominal cavity. In a healthy animal, there should be no more than a nominal amount of fluid present in the abdominal cavity. The purpose of this fluid is to keep the organs “gliding” smoothly around each other. In fact, the amount of fluid in a healthy dog’s abdomen should be low enough not to appear on radiography. Any imaging that reveals the presence of free fluid is an indication of a serious health problem. Ascites is a symptom of many other conditions, including liver and cardiac disease, specifically congestive heart failure (CHF). In congestive heart failure, the heart cannot pump enough blood throughout the body, causing fluid to swell in tissues both in the lungs and stomach. The dog’s overall prognosis will depend on the source of the swelling or ascites. 

Another possible cause for the abdominal distension is a pooling of blood. This could occur after e.g. a splenic tumour rupture, coagulation defect or trauma.

Rapid-pooling gas, or “bloat,” is another emergent cause of abdominal distention in a canine. In the veterinary world, bloat is an alarming term that signifies something far different than feeling full after a big dinner. Bloat, in a dog, will cause the abdomen to become untenably swollen and tight. The abdomen may take on an uneven appearance in which one part of the abdomen distends beyond another. If your dog appears to be bloated, this is a highly emergent situation, and the dog must get veterinary care immediately. 

Other common causes of abdominal distension in dogs include pregnancy, which is distinguishable from other conditions due to the presence of swollen mammary glands and teats. Obesity is another possibility; in this case, the stomach should be soft and fat should be visible elsewhere on the body, not only in the stomach area.

Some medical conditions such as Cushing's disease are known to cause abdominal swelling due to the weakened abdominal muscles and enlarged liver.

Tumours growing in the abdomen will inevitably result in some visible swelling once they reach a certain size.

Puppies that are bloated are commonly infested with parasites (intestinal worms).

In canines, a distended abdomen may signify a disease or dysfunction related to a major organ such as the heart, or another condition such as pregnancy or obesity.

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Symptoms of Distended Abdomen in Dogs

Clinical signs associated with distended abdomen in dogs include:

  • Visibly distended abdomen
  • Lethargy
  • Weakness
  • Signs of discomfort when touched
  • Difficulty breathing
  • Coughing
  • Lack of appetite
  • Vomiting
  • Diarrhea
  • Urinary changes
  • Exercise intolerance
  • Panting
  • Pale gums
  • Exercise intolerance

Causes of Distended Abdomen in Dogs

  • Bloat - A very serious condition in which gas rapidly fills the stomach
  • Bleeding -An emergent condition in which blood is pooling in the abdomen
  • Free fluid (also called abdominal effusion or ascites) - A serious condition when fluid builds in the abdomen, may signify disease or failure of major organs
  • Pregnancy - The female usually presents with a swollen abdomen by 6 weeks of expectancy, and will also have swollen mammary glands 
  • Obesity - The abdomen should be soft and weight should be distributed around the body
  • Growths/tumors - Benign or may signify a disease such as cancer
  • Liver disease
  • Heart disease
  • Uterine infection (Pyometra)
  • Hormonal condition i.e. Cushing's Disease
  • Peritonitis - Inflammation of the peritoneum, the tissue that lines the abdominal wall and covers most of the abdominal organs

Diagnosis of Distended Abdomen in Dogs

The veterinarian may make an initial diagnosis based upon the dog’s presentation of symptoms at the physical examination. Radiography and ultrasounds may confirm the presence of fluid in the abdomen, or perhaps reveal another cause. Blood (CBC), urine and sample of (if any) fluid will be subject to laboratory testing, and may offer insight into the dog’s overall condition. Other testing will be performed based on the veterinarian’s suspicions.

Treatment of Distended Abdomen in Dogs

Treatment options will depend upon the cause of the abdominal distension, and any underlying conditions. If there is a fluid buildup, that will have to be eliminated; however, without treating the source of the ascites, improvement is not likely. Treatment examples would be:

  • Obesity - The veterinarian will advise on a healthy weight loss and maintenance program
  • Growths - A tumor may need to be removed
  • Bloat - Surgery may be necessary in order to reverse volvulus (twisting of the stomach)
  • Fluid - Draining will be required and the underlying cause must be addressed e.g. diuretics can prevent the fluid build up associated with heart disease
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Recovery of Distended Abdomen in Dogs

As with any illness, provide your dog with a quiet place to rest and heal. Follow veterinary advice regarding any nutritional changes, and follow-up medications. The dog’s prognosis will depend upon the cause of the distension. Keep a watchful eye on the abdominal area, and notify the veterinarian if changes are noted.

Conditions related to a distended abdomen can be expensive to treat. To avoid high vet care expenses, secure pet health insurance today. The sooner you insure your pet, the more protection you’ll have from unexpected vet costs.

Distended Abdomen Questions and Advice from Veterinary Professionals


Labrador Retriever



Eleven Years


46 found this helpful


46 found this helpful

My pet has the following symptoms:
Distended Abdomen
Took dog on a walk this morning. He used the restroom and all of a sudden refused to walk. I noticed his belly was really distended and he was just saying back and forth. Have him home now and is laying down but belly still painful. Not sure if this is an emergency or not

Dec. 18, 2020

Answered by Dr. Michele K. DVM

46 Recommendations

Thank you for your question. I do think that this is an emergency, yes. I would call that an 'acute abdomen', and it would be best to have him seen by your veterinarian right away. I hope that all goes well for him, and that he feels better very soon.

Dec. 18, 2020

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Eleven Years


22 found this helpful


22 found this helpful

My pet has the following symptoms:
Stomach swelling titties filling up not active won't eat but will drink water not pooping

Dec. 18, 2020

Answered by Dr. Sara O. DVM

22 Recommendations

Hello so sorry to hear that your dog is having issues. Heart issues can cause her stomach to fill up with fluid. Also other things such as a mass in her abdomen or pyometra could cause her to have issues. From your description, I think the best thing is for her to see your vet for an exam. There are many things that would really need vet attention right away.

Dec. 18, 2020

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