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Other Names: Waterbelly, Pulmonary Hypertension Syndrome, Dropsy

Ascites refers to the accumulation of fluid within the peritoneal cavity. Mild or early stages of ascites may have no associated clinical signs; however as more fluid accumulates, it will cause chickens to appear bloated with an enlarged or swollen-looking abdomen (called abdominal distention). The fluid present (ascitic fluid) is usually serous in nature, which is a pale yellow and clear. Ascites can be caused by pulmonary arterial hypertension (PAH), liver disease, congestive heart failure, kidney failure, and a manifestation of advanced cancers of the organs in the abdominal cavity.
  • Portal hypertension-related Ascites: This form of ascites is caused by increased pressure in the blood flow to the liver as the main contributor. It is associated with excess oxygen demands placed on the chicken's body. What happens is that the chicken's heart and lungs will continue to attempt to supply the body with enough oxygen, and in doing so, eventually it will pump excess blood into the lungs. Over time, the chicken's heart muscle will get larger and thicken as a result of the increased work, preventing the right heart valve from closing. This results in the accumulation of blood within the liver, which eventually leaks into the body cavity, causing ascites. Contributing risk factors include
  • Malignant-related Ascites: This form of ascites is typically a manifestation of advanced cancers of the organs in the chicken's abdominal cavity. The growth of the mass (or tumor) pressing on the portal vessels inside the abdominal cavity result in leakage of fluid into the body cavity.

Clinical Signs

Enlarged abdomen
Difficulty breathing
Gurgling sounds
Bluish skin discoloration
Ruffled feathers
Reluctance to move
Sudden death (often when frightened)
Panting without heat stress
Sagging abdomen
Coughing (chronic)


  • History
  • Clinical signs
  • Physical exam
  • Radiographs
  • Ultrasonography
  • Chemistry panel
  • PCV
  • Total WBC
  • Necropsy


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.
Drainage or aspirationA procedure that should be performed by your veterinarian, in order to remove the extra fluid from the chicken's abdominal cavity, to help improve breathing function.M Pees et al



  • Prevent hens from becoming obese:
  • Feeding karaf (Kelussia odoratissima) leaves and stems at 0.5-0.75% of diet: Ahmadipour et al, 2015
  • Feeding quality, high-protein diets which include supplemental dietary arginine (an important amino acid) : Khajali, et al., 2016
  • Feeding a low-fat diet : Khajali F et al., 2016
  • Partial substitution of sodium bicarbonate for sodium chloride in diet : Khajali F et al., 2016
  • Implementing a low-fat diet: Khajali F et al., 2016


can cause a mortality of up to 8% in broiler flocks (20-30% in heavy flocks)

Scientific References

Age Range

It is most commonly found in broilers and older laying hens

Risk Factors

  • Exposure to poor air quality
  • History of respiratory disease
  • Exposure to elevated ammonia levels due to unsanitary conditions and poor litter management.
  • Living at high altitudes (i.e., above 3,500 m)
  • Exposure to high temperatures that increase the metabolic rate
  • High levels of sodium in feed or water
  • Exposure to second-hand cigarette smoke
  • Heavy 'meat-type' birds such as broilers and turkeys are highly susceptible to cardiovascular diseases.