abdominal distension in dogs

Abdominal Distension in Dogs

Overview of Canine Abdominal Distension

Abdominal distension is an abnormal enlargement of the abdominal cavity. This term is usually reserved for abdominal enlargement due to causes other than simple obesity.

In dogs, one cause of abdominal distension is fluid accumulation. The types of fluids include blood from internal hemorrhage (bleeding), urine from a tear in the urinary tract, exudate (cellular fluids similar to pus) from infection as with feline infectious peritonitis, and transudates (clear fluids), that are leaked from vessels.

Another cause of abdominal distension is enlargement of any abdominal organ including the liver, kidneys, or spleen. Distension of the stomach with air (“bloating“) or fluid or distension of the uterus (womb) during pregnancy, can result in abdominal distension.

Tumors within the abdomen can also cause abdominal distension. The tumor may be malignant (an invasive cancer), or benign, (abnormal but not spreading to other tissues). Tumors can involve any of the abdominal organs, including the intestines or lymph nodes (glands).

Loss of abdominal muscle tone, with or without significant weight gain, also can lead to abdominal distension.

Pressure from the abdomen pushing into the chest may make breathing more difficult and pressure within the abdomen may decrease the appetite. NOTE: It is important to recognize abdominal distension because it can be a symptom of potentially life-threatening diseases and should be investigated thoroughly.

What to Watch For

Diagnosis of Abdominal Distension in Dogs

Veterinary care should include diagnostic tests to determine the cause of the abdominal distension and provide information on which to base recommendations for treatment. Diagnostic tests that your veterinarian may wish to perform include:

Treatment of Abdominal Distension in Dogs

Treatment for abdominal distension is dependent upon the underlying cause (diagnosis). Treatment may include:

Home Care

If you notice abdominal distension and your dog is acting sick, call your veterinarian. If abdominal distension is associated with vomiting, wretching or collapse, call your veterinarian immediately. These symptoms can be life-threatening.

In-depth Information on Abdominal Distension in Dogs

The abdominal cavity contains vital organs such as the stomach and intestines, liver, spleen, pancreas, kidneys and urinary bladder. It also contains numerous blood vessels, lymph vessels and lymph nodes are also present in the abdominal cavity and is lined with a thin, specialized membrane (the peritoneum) that contains the contents within a sterile environment.

Causes of Abdominal Distension in Dogs
Abdominal distension can be caused by fat accumulation, fluid accumulation in the peritoneal space, enlargement of abdominal organs or weakness of the abdominal muscles. The fluids that cause abdominal distension can be blood, urine, exudate, transudate or any combination of these.

Causes of these different fluid types are listed below:


Blood can fill the abdomen because of trauma, erosion of blood vessels, failure to form blood clots normally, or tumors causing organs to rupture.


Urine can fill the abdomen and cause distension. Rupture of the urinary tract is generally the result of trauma (such as being hit by a car).


Exudates are thick, cellular fluids. These fluids often result from infection within the abdominal cavity. Dogs may develop exudate in response to bacterial infection as a result of a penetrating injury or a tear in the gastrointestinal tract. This can occur in dogs with a string-type foreign body that “saws” its way through the intestine. Exudates may also accompany cancers of the abdomen (neoplastic effusion) or result from obstruction to drainage of lymphatic fluid (chylous effusion). Lymphatic fluids are fluids that surround cells and are collected and transported by lymph vessels into the bloodstream.


Transudates are clear fluids, without many cells or much protein, resulting from pressure blocking normal blood flow or from decreases in the protein (albumin), which holds water in the blood. Examples of processes likely to produce transudates include:

Organ Enlargement

Enlargement of any abdominal organ can cause distension. Enlargement of the liver, kidneys or spleen may be due to obstructions of fluid flow (either blood flow or urine flow) or infiltration with cells (cancer or leukemia cells or inflammatory blood cells).

Other causes of abdominal distension that are not caused by fluid accumulation include:

Diagnosis In-depth

Diagnostic tests are needed to recognize abdominal distention and exclude other diseases. These tests may include:

Treatment In-depth

Exact treatment requires establishment of a diagnosis. Abdominal swelling in itself is seldom a threat to life, so symptomatic (nonspecific) treatments are often not indicated. However, severe abdominal distention can place pressure on the chest and interfere with comfortable breathing. The following is a list of potential nonspecific (symptomatic) treatments that may be applicable. These treatments cannot be a substitute for more definite treatment.

Follow-up Care for Dogs with Abdominal Distension

Optimal treatment and follow-up for your dog requires a combination of home and professional veterinary care. Specific recommendations will be dependent upon the underlying cause of the abdominal distension.