Investigation of high gamma-glutamyltransferase syndrome in California Thoroughbred racehorses

BackgroundIncreases in serum gamma-glutamyltransferase (GGT) activity have been reported in Thoroughbred (TB) racehorses and associated with maladaptation to training but the underlying etiology remains unknown.Hypothesis/objectivesClassify the etiology of high GGT syndrome in racing TBs by assessment of pancreatic enzymes, vitamin E concentrations, and both a candidate gene and whole genome association study. We hypothesized that a genetic variant resulting in antioxidant insufficiency or pancreatic dysfunction would be responsible for high GGT syndrome in TBs.AnimalsA total of 138 California racing TBs. Amylase: n=31 affected (serum GGT activity ≥60 IU/L), n=52 control (serum GGT activity