Fatty liver hemorrhagic syndrome is a metabolic disorder of chickens related to a high-energy diet and reduced exercise, which causes fatty-friable liver that is prone to hemorrhage and rupture. Birds that are fed a high-energy diet, eg high levels of maize, seeds and nuts, are more susceptible to obesity. Hot weather also plays a part as it can result in less activity, especially in caged birds, causing weight gain and increased stress levels. There also appears to be a hormonal factor as chickens with a high growth rate and high-performance egg layers are more prone to the condition. 

Clinical signs

Obesity and reduced egg production is seen in affected birds. Pale comb and wattles are another presenting sign, and sudden deaths within the flock are likely. The condition is most common in older laying hens. Females are predisposed due to increased serum estrogen which causes an increase in liver fat content. 

Diagnosis

Diagnostic imaging, such as radiography and ultrasonography, will confirm hepatomegaly. Serum biochemistry may reveal increased AST, ALT, GGT, cholesterol and triglycerides. A celiotomy or celioscopy can be performed to obtain liver biopsy for histopathology. Findings show distention of hepatocytes with vacuolation, hepatocyte rupture, inflammation, necrosis, and regeneration.

Gross autopsy findings include liver hemorrhage, liver and/or kidneys friable and pale or yellow in color. This is due to a raised fat content. There will be substantial interstitial fat, and evidence of hepatic rupture, eg hemoabdomen, hepatic capsule blood clots, pale carcass. Subclinical cases may demonstrate subcapsular hemorrhage of kidneys/liver, old hematomas, blood clots and areas of organ necrosis.

Treatment

The underlying cause must be treated through dietary nutrient correction, dietary energy levels (carbohydrate:fat ratio) and increased exercise. The feed particle size can be reduced by mashing the pellets to slow feed consumption. Increasing antioxidants (vitamin E, selenium, L-tryptophan) will provide hepatic support. Increase fat catabolism and treat hepatic lipidosis with anabolic steroids and levothyroxine. Fat metabolism can be increased with amino acids, carnitine and methionine. 

Prognosis

The prognosis depends on the underlying cause and severity of pathology. Subclinical cases with prompt intervention and diet changes may respond well. If there are sudden deaths, prognosis is guarded for the rest of the flock. Fatty liver hemorrhagic syndrome can be prevented with the appropriate diet and activity levels.

References

• Fatty liver hemorrhagic syndrome

Content provided from Vetstream's Vetlexicon Avis - https://www.vetlexicon.com/avis

Vetlexicon is the world’s largest peer-reviewed online clinical reference source. All our content is written and peer-reviewed by over 1,000 of the world’s leading veterinarians, ensuring relevance, accuracy and quality.