Fatty liver disease is a common illness in a variety of chickens including the Black Australorp. This particular disease is most often caused by nutritional and metabolic issues such as a lack of biotin (or a water soluble B vitamin). A type of fatty liver disease is the Fatty Liver Hemorrhagic Syndrome (FLHS), which is caused by many related factors including hormonal, nutritional and toxicological causes. This disease can affect a single Black Australorp or the entire flock no matter their ages. It can occur when large amounts of fat are deposited into the liver. The liver cannot break down such large amounts and may become enlarged and quit functioning. When this happens the chicken can hemorrhage from the swollen liver and even die. FLHS is known to occur in laying hens that are straining to lay an egg. For additional information, contact your veterinarian Marquette, MI.