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Pericardial Effusion in Dogs

Learn about pericardial effusion in dogs.

The pericardium or pericardial sac is a thin layer of tissue that surrounds a dog's heart. Under normal conditions, the pericardium contains a tiny amount of clear fluid. If too much fluid accumulates inside the sac, it negatively affects the heart's ability to pump and is called pericardial effusion.

Causes of Pericardial Effusion in Dogs

Pericardial effusion can be caused by:

  • Tumors in the heart or on the pericardium
  • Inflammation of the pericardial sac, either from infection or an unknown cause
  • Trauma, such as being hit by a car
  • Conditions that interfere with proper blood clotting
  • Congestive heart failure
  • Conditions causing low blood protein levels (hypoalbuminemia)

Signs of Pericardial Effusion in Dogs

Signs may develop suddenly or more slowly over time and can include:

  • Fluid accumulation in the abdomen, which may cause visible abdominal enlargement
  • Cough
  • Decreased appetite
  • Lethargy
  • Exercise intolerance
  • Collapse
  • Sudden death

Dog Breeds More Commonly Affected by Pericardial Effusion

The dog breeds more commonly affected by pericardial effusion are those that are prone to being affected by its underlying causes and include:

  • Boxers
  • Bulldogs
  • Golden retrievers
  • Weimaraners
  • German Shepherds

Diagnosis of Canine Pericardial Effusion

A veterinarian may suspect pericardial effusion when an owner describes the signs seen at home. Additionally, during a thorough exam, the vet may find some or all of the following:

  • Pale mucous membranes
  • Weak pulses
  • Muffled heart sounds when listened to with a stethoscope
  • Fever (if the condition is related to infection)
  • Enlarged liver
  • Low blood pressure

X-rays may show fluid accumulation in the abdomen, and the heart may appear abnormally smooth, round, and enlarged. Ultrasound of the chest can also reveal the pericardial effusion.

A sample of the fluid in the pericardium may be collected with a needle for analysis under the microscope. That could help diagnose the underlying cause of the pericardial effusion.

Treatment of Canine Pericardial Effusion

The treatment of pericardial effusion revolves around addressing the underlying cause. For example, a tumor requires surgical removal and/or chemotherapy. Heart failure requires medications to attempt to support heart function.

In cases where the dog is in critical condition, a veterinarian may attempt to remove enough fluid from the pericardial sac to relieve the emergency. However, without treatment for the underlying condition, the liquid will simply build up again.

The prognosis for a dog with pericardial effusion depends entirely on the individual's underlying condition.

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