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Heart Failure

Other Names: Sudden Death Syndrome, "flip-over Disease"

Heart failure (HF) is very common in fast-growing, "meat-type" chicken breeds. This is due to their unnaturally fast growth rate coupled with their excessively large body mass, relative to the size of their organs---specifically their respiratory system and heart. HF occurs when the bird's heart can no longer cope with pumping the full amount of blood needed in each heartbeat. It may only affect the right ventricle (known as right-sided heart failure) or the left ventricle (left-sided heart failure), or both.

What are the Presenting Clinical Signs?

When chickens have heart failure, they usually develop signs relating to having a more difficult time breathing and show reduced exercise tolerance. Chickens with right heart failure are more likely to develop ascites and a build up of excess fluid in their abdomen, or cause an increase in size of the liver.

Clinical Signs

Difficulty breathing
Reduced exercise tolerance
Sudden death
Enlarged abdomen
Temporary loss in consciousness


  • History
  • Clinical signs
  • Physical exam
  • Radiographs
  • Echocardiography

Reported Cases

  • Case 1: Right heart failure in a Penguin A 19-year-old male African penguin was presented with coelomic distention after a 6-week history of lethargy and decreased appetite. Results of radiographs showed loss of coelomic detail, and ultrasound and computed tomography results revealed coelomic fluid and dilated hepatic veins. Echocardiography revealed moderate right atrial enlargement. Findings were consistent with right-sided cardiac disease. Treatment with furosemide initially reduced ascites, but the clinical condition worsened weeks later and enalapril, pimobendan, and sildenafil were added to the medical therapy. At 12 weeks after presentation, results of an echocardiogram revealed persistent right atrioventricular valve regurgitation, moderate ascites, and dilation of hepatic veins. Clinical signs of right heart failure were managed through adjustments in medical therapy and coelomic fluid aspiration, but the bird died 18 weeks after initial presentation. Gross and microscopic findings were consistent with valvular insufficiency and right-sided heart failure. Ref


Supportive careIsolate the bird from the flock and place in a safe, comfortable, warm location (your own chicken "intensive care unit") with easy access to water and food. Limit stress. Call your veterinarian.



  • Restrict their diet, for they will eat any food put in front of them and don't know when to stop (they were breed to do this)
  • Don't house them with other chicken breeds if they are given free access to any feed that smaller breeds may require.
  • Always provide unlimited access to fresh, clean water.
  • Do not feed them anything meant for "meat-birds" or "grower" feed, for this is is designed to promote rapid weight gain. Feed them a layer pellet in restricted amounts, with fresh vegetables and fruits.
  • Provide pasture grass to forage on which will also keep them active

Scientific References

Risk Factors

  • Fast growing, "meat-type" chicken breeds, such as the Cornish ("broiler")
  • Feeding them "meat-bird" or "grower" feed
  • Allowing them unrestricted access to feed