Ascites in Dogs

Causes, Treatment, and Prevention

Dog laying on a rug

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Ascites is an abnormal buildup of abdominal fluid that can occur in any dog but is a result of an underlying disease so ignoring the symptoms can be detrimental to your dog's health. Knowing the signs of ascites, what it may mean for your dog, and how it is treated is helpful for any pet owner.

What Is Ascites in Dogs?

Ascites is not a disease itself, but it is free fluid floating in the dog's abdomen that signals a serious medical problem. The abdomen contains many organs including the kidneys, intestines, stomach, liver, spleen, bladder, and others but there is normally very little fluid that is outside one of these structures. When ascites occurs, these organs will be surrounded by fluid that is freely floating around in the abdomen.

Symptoms of Ascites in Dogs


  • Swollen abdomen
  • Lethargy
  • Difficulty breathing/panting
  • Weight gain
  • Decreased appetite
  • Vomiting
  • Discomfort

Swollen Abdomen

The most obvious sign of ascites in dogs is a swollen belly. This swelling or distension is due to the excess fluid that is accumulating in the abdomen and makes a dog appear bloated. Just like filling a balloon with water will cause it to expand, an abdomen that is filling with fluid will be larger and rounder than normal.


As with most animals, a sick dog with ascites symptoms will behave listless because its organs and other systems are not functioning well.

Difficulty Breathing and Panting

The swelling puts pressure on the diaphragm which can make it harder for a dog with ascites to breathe. This can also result in panting.

Weight Gain

Finally, weight gain may be noted due to the excessive fluid in the abdomen.

Decreased Appetite

Your dog will likely lose its appetite because of the swollen abdominal area and feeling of fullness.


Vomiting may be seen in cases of dogs with ascites where the pressure of the fluid is pushing on the stomach and diaphragm.


Abdominal swelling will cause discomfort or pain in your dog.

Causes of Ascites

Ascites occurs as a result of an underlying condition with some being more common than others.

  • Liver issues: Portal hypertension is one kind of liver issue that commonly causes ascites in dogs. The free fluid that occurs due to liver problems usually looks similar to water and is due to circulation issues and low protein levels in the body.
  • Internal bleeding: If an internal organ has been traumatized, there could be internal bleeding. This blood can accumulate in the abdomen.
  • Bladder rupture: If a bladder can't normally empty or it's been traumatized it can rupture. As a result, urine can accumulate in the abdomen.
  • Peritonitis: Peritonitis is an infected abdominal lining that is inflamed. Ascites can result from this.
  • Cancer: If cancer is inflaming the abdominal lining it can cause ascites. The ascites may be due to a bleeding tumor or circulatory issues.
  • Heart failure: Similarly to why liver issues can cause ascites, heart failure can lead to circulation issues and result in ascites. This is a fairly common reason for ascites in dogs.
  • Kidney issues: Kidney dysfunction can cause a dog to develop ascites. This is due to protein lost through the kidneys.

Diagnosing Ascites in Dogs

Your veterinarian will perform a full physical examination and may recommend X-rays be taken to see if free fluid is in the abdominal cavity along with any abnormalities that could cause the ascites. If ascites is noted on the X-ray, your vet may order blood tests, urine tests, and an ultrasound to find the underlying reason for the condition.

A needle may be inserted into your dog's abdomen to see if fluid is present. If it is, this fluid may then be analyzed by a laboratory to see what kind of fluid it is and help figure out where it is coming from.


The treatment of ascites will vary depending on what caused it in the first place. Here are the three types of treatment for ascites in dogs:

  • Surgery: Sometimes surgery will be needed to address the cause.
  • Draining: Your veterinarian may relieve the pressure by draining the fluid. The procedure, called an abdominocentesis, may need to be done on a fairly regular basis if the underlying reason for the ascites is not corrected with surgery, medications, and diet changes. Draining fluid can usually be done without sedation or anesthesia using a needle and syringe but it only helps to manage the symptoms the ascites causes, not the underlying reason for it.
  • Medication and diet: Various medications, such as diuretics, and special diets, such as a low-sodium type, will typically be used as part of ongoing treatments, as well.

Prognosis for Dogs With Ascites

A dog's prognosis will depend on the underlying cause of the condition. Ascites does not indicate certain fatality, and a dog may be able to live with treatment for an extended period. However, often it can signal a poor outcome for the dog.

How to Prevent Ascites

Since there are so many causes of ascites in dogs it is hard to prevent it. The best thing you can do to help keep your dog healthy and prevent ascites from occurring is to have regular veterinary examinations and blood work performed to look for any abnormalities in its body. This can help detect diseases that can cause ascites in their early stages and prevent fluid from building up in the abdomen.