Use of Laboratory Testing to Diagnose Liver and Biliary Dysfunction in the Horse

Abstract

Laboratory tests commonly used for detection or confirmation of equine liver disease comprise the measurement of a series of enzymatic parameters as serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), γ-glutamyl transferase (GGT), glutamate dehydrogenase (GLDH) and sorbitol dehydrogenase (SDH) and biochemical measurements such as proteins, globulins and albumin, bile acids, triglycerides, cholesterol, bilirubin, urea, ammonia, and glucose. Complementary tests might help to categorize a wide spectrum of liver diseases as they reflect the different functions of the liver, and excretion of anions (bilirubin), hepatocellular integrity (enzymes), gall bladder function and free flow (bilirubin and ALP) and protein synthesis. They could indicate the potential cause of liver disease, assesses the severity of damage, and helps to formulate the prognosis and to evaluate the effectiveness of treatment. Nevertheless, some diseases can be diagnosed more specifically using other techniques diagnostic such as liver biopsy or ultrasound, as well as in many asymptomatic patients. Throughout this review, we will address the interpretation of the main laboratory tests used to detect lesions and to evaluate the function of the liver in the horse