Haematological and biochemical changes in horses competing in a 3 Star horse trial and 3-day-event

F.M. Andrews
Dennis R. Geiser DVM, University of Tennessee - Knoxville
S.L. White
L.H. Williamson
P.L. Maykuth
E.M. Green

Abstract

Haematological and biochemical changes in horses competing in the Endurance Test (Phase T and D) of an advanced Horse Trial (HT, n = 22) and the Endurance Test (Phases A-D) of an advanced (CCI***) 3-day-event (TD, n = 11) over a similar course on the same day were studied. Environmental conditions were cool (5.5-11.1C). Blood samples were collected from the horses in each group the evening before the Endurance Test, within 60 s after, and 10 min after completion of Phase D (cross-country jumping). The packed cell volume and serum creatinine concentration were higher in the TD group but not significantly. The serum total protein, serum albumin, plasma sodium and glucose concentrations, and creatine kinase and aspartate aminotransferase activities were significantly higher and serum chloride and serum inorganic phosphate concentrations significantly lower in the TD group after exercise when compared to the HT group. It was concluded that horses competing in the 3-day-event had greater fluid and electrolyte losses, reduced glomerular filtration, higher glycogenolysis and greater leakage of enzymes from working muscles during competition than horses competing in the horse trial.