This study investigated the levels of total glutathione (GSH) in different forms of hepatic disease in 63 dogs and 20 cats as well as in 12 healthy dogs and 15 healthy cats. GSH was measured in liver biopsy specimens. They conclude that GSH levels are commonly low in necroinflammatory liver conditions, extrahepatic bile duct obstruction and feline hepatic lipidosis, with cats having a probable higher risk for lower GSH levels.