Abdominal Distension in Cats

Overview of Abdominal Distension in Cats

Abdominal distension is an abnormal enlargement of the cat’s abdominal cavity. This term is usually reserved for abdominal enlargement due to causes other than simple obesity. For information on obesity, please read Obesity in Cats.

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 in cats. 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 Cats

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 Cats

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

Home Care

In-depth Information on Feline Abdominal Distension

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 Abdominal Distension in Cats

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. In cats, feline infectious peritonitis (FIP), is an important cause of exudative abdominal fluid. Cats 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 cats 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 blood stream.


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

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 and is lined with a thin, specialized membrane (the peritoneum) that contains the contents within a sterile environment.

Abdominal distension can be caused by many different diseases or disorders.​​

Diagnosis In-depth

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

On an individual basis, additional diagnostic tests may be needed to determine and/or diagnose other medical problems or to understand the overall impact abdominal distention may have on your cat. These 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.