Occurrence and Pathology of Fatty Liver Haemorrhagic Syndrome in Chickens in and Around Hyderabad, India

Abstract

Fatty liver haemorrhagic syndrome (FLHS) is a non-infectious metabolic disease, mainly of laying hens, in which fat accumulates in the liver and can rupture, causing fatal intra-abdominal haemorrhage. This study describes the occurrence and pathology of FLHS in chickens in and around Hyderabad, Telangana, from July to December 2025. Carcasses were collected from 45 poultry farms and from cases submitted to the Department of Veterinary Pathology, Rajendranagar, for post-mortem examination. FLHS caused 65 deaths across two outbreaks, a case prevalence of 8.56% and the highest disease-specific mortality (3.25%) among the conditions studied. No deaths occurred before 22 days of age. Mortality was 4.00% at 22–28 days and 5.62% in birds older than 29 days. Grossly, the livers were enlarged, soft, friable and discoloured tan to yellow or orange, with intraparenchymal and subcapsular haemorrhages and blood clots in the coelomic cavity. Histopathology showed variable hepatocellular vacuolation, sinusoidal haemorrhages, hepatocyte pyknosis and chromatin margination. The authors conclude that FLHS is an important cause of mortality in older birds in the study area.