Birds with this disease have large amounts of fat deposited in their liver and abdomen.
[2] In some cases the disease is fatal, usually as a result of blood loss from an internal hemorrhage in the liver.
[2] Fatty liver hemorrhagic syndrome is "the major cause of mortality in laying hens.
"[4] Excessive dietary energy intake is believed to be the cause of fatty liver hemorrhagic syndrome.
[3] Birds housed in cages will more likely be affected because they are unable to exercise to burn off the extra dietary energy.