Ascites in Dogs

Overview of Ascites in Dogs

Ascites is the abnormal accumulation of fluid in the abdominal cavity. The volume of the fluid can be quite subtle, or it may be significant, causing distention of the abdomen. In dogs, ascites has many causes, most of which can be very serious. Ascites is caused by the leakage of fluid into the abdomen from blood vessels, lymphatics, internal organs or abdominal masses.

Causes of Canine Ascites

What to Watch For

Diagnosis of Ascites in Dogs

Certain diagnostic tests must be performed for a definitive diagnosis of the underlying cause of ascites. The following tests should be considered:

Based on the results of these initial tests, further diagnostics might include:

Treatment of Ascites in Dogs

An accurate diagnosis is needed for proper therapy. Pending a definitive diagnosis, certain treatments may be appropriate:

Home Care

Keep your dog calm and minimize stress. Make sure your pet stays warm and provide fresh water if your pet wants to drink. Seek veterinary care immediately if your pet is having trouble breathing or is extremely weak.

In-depth Information on Ascites in Dogs

Ascites, itself, usually does not cause a problem, but the primary disease process causing the ascites can be a serious condition. Ascites is usually produced slowly and in small amounts; however, if a large amount of fluid is produced, or rapidly produced, an emergency situation may exist. Large amounts of free fluid in the abdomen may compress the diaphragm, leading to respiratory compromise and difficulty breathing. Fortunately, this is a rare occurrence.

Another potential emergency situation is the rapid onset of ascites. If the ascites develops quickly, it is often associated with profound weakness or shock. The loss of intravascular (within the blood vessels) blood volume may lead to acute anemia and shock as fluid leaves the blood vessels and moves freely into the abdominal cavity. The most common cause of such an event is the rupture of a blood vessel within the abdominal cavity. Bleeding tumors within the abdomen or traumatic injury are likely causes.

Most of the time, the fluid buildup is more gradual and an emergency situation is not present. Any amount of ascites is a significant finding, however, and steps should be taken to find a diagnosis. Ascites has many different causes and establishing a diagnosis is usually not difficult. A good physical exam, basic blood tests and evaluation of the ascitic fluid often lead to the diagnosis, or they provide a direction upon which further diagnostics need to be done.

Hypoalbuminemia Causes

Hypoalbuminemia is a decrease in serum albumin levels. Albumin is available through the diet, but it is also produced in the liver. The kidney functions to maintain albumin concentration in the plasma by preventing its excretion in the urine. Normal gastrointestinal function is needed for proper absorption. Albumin is responsible for much of the colloidal osmotic pressure of the blood, and thus is an important factor in regulating the exchange of water between the plasma and the interstitial compartment (space between the cells). Decreases in the albumin level (usually under 1.5 gm/dl) lead to a pressure gradient that causes fluid to leak out of the blood vessels, producing ascites.

Obstructive Causes

Obstruction of blood flow within the abdomen can result in ascites. This obstruction may cause a leakage of fluid from the veins or lymphatics and into the peritoneal (abdominal) cavity depending on the location.

Other Causes

Diagnosis In-depth

A complete history and physical examination is very important in determining the diagnostic aids of choice. Proper evaluation will determine the depth of the diagnostics needed.

Therapy In-depth

One or more of the diagnostic tests described above may be recommended by your veterinarian. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe. The following nonspecific (symptomatic) treatments may be applicable to some, but not all, pets with ascites. These treatments may reduce severity of symptoms or provide relief for your pet. However, nonspecific therapy is not a substitute for definite treatment of the underlying disease responsible for your pet’s condition.

The most important aspect of treating ascites is to determine how quickly the ascites has developed, and the clinical condition of your pet. If the ascites has developed slowly, and your pet is fairly strong, then emergency treatment is generally not required. If the ascitic fluid has developed rapidly, it is often associated with weakness and emergency care is indicated. Appropriate treatment pending a diagnosis of the primary cause of the ascites may include: