Pericardial Effusion In Dogs & Cats

What is pericardial effusion?

  • Pericardial effusion is the abnormal accumulation of fluid within the sac surrounding the heart (pericardium).
  • There is normally only a very small amount of fluid in that sac to protect the heart and provide lubrication to prevent friction between the moving heart and surrounding organs.
  • Pericardial effusion in dogs and cats usually causes fluid accumulation in the belly and causes symptoms of weakness, breathing difficulties, and sometimes collapse.

How is it diagnosed?

  • An echocardiogram (ultrasound or sonogram of the heart) by a veterinary cardiologist is the gold standard for definitive diagnosis.
  • Physical examination, chest x-rays, electrocardiograms and overall history can also assist in making the diagnosis of pericardial effusion.

What Causes Pericardial Effusion in Dogs & Cats?

  • The most common condition is bleeding from a tumor – some are aggressive and some are not.
  • If a tumor is seen, consultation with a veterinary oncologist is often recommended.
  • Infections and heart failure can also cause fluid to abnormally accumulate in the heart sac.
  • Sometimes there is no known cause (idiopathic) – up to two thirds of patients do not have an identifiable cause on initial examination.
image of heart with pericardial fluid surrounding the heart
Echocardiogram image of heart with pericardial fluid surrounding the heart with all four chambers shown. (RV-right ventricle, RA-right atrium, LV-left ventricle, LA-left atrium)
image of heart with labels
Diagram depicting the relationship between the pericardium and heart.

What is the prognosis?

How is Pericardial Effusion in Dogs & Cats treated?