Hydration and electrolyte balance in horses during an endurance season
Article first published online: 8 NOV 2010
© 2010 EVJ Ltd
Equine Veterinary Journal
Special Issue: Proceedings of the 8th International Conference on Equine Exercise Physiology
Volume 42, Issue Supplement s38, pages 98–104, November 2010
How to Cite
ROBERT, C., GOACHET, A.-G., FRAIPONT, A., VOTION, D.-M., Van ERCK, E. and LECLERC, J.-L. (2010), Hydration and electrolyte balance in horses during an endurance season. Equine Veterinary Journal, 42: 98–104. doi: 10.1111/j.2042-3306.2010.00198.x
- Issue published online: 8 NOV 2010
- Article first published online: 8 NOV 2010
- [Paper received for publication 10.01.10; Accepted 11.06.10]
Reasons for performing study: Limited information exists about the physiological training-induced changes in electrolyte balance of horses competing in long distance endurance races.
Objectives: To determine the effects of endurance training and racing on hydration and electrolyte balance in horses.
Methods: Blood and urine were sampled at rest in 8 endurance horses before training and after two 11 week training periods (T1 and T2). Each training was followed by a 120 km endurance ride and horses were sampled before, during and 2 h after the rides. Blood was analysed for packed cell volume (PCV), total protein (TP), urea, creatinine and electrolyte concentrations. Urine was analysed for pH, specific gravity, creatinine and electrolyte concentrations, which allowed calculation of fractional excretion of electrolytes (FE). Changes associated with training and with the rides were assessed using a Student paired t test (P≤0.05).
Results: Plasma TP, urea, creatinine and sodium concentrations increased during T1 and PCV decreased significantly during T2. FECl increased during T1 then decreased. FEK increased significantly during both training periods. Other blood and urine parameters did not show remarkable changes with training. PCV, plasma TP, urea, creatinine and total Ca concentrations increased and plasma Na+ and Cl- concentrations decreased during both rides. Urine concentrations of Na+, K+ and Cl-, FENa and FECl decreased during the rides while urinary creatinine increased. FEK increased during the first part of the rides then decreased.
Conclusions: These data contribute to the understanding of changes associated with training and prolonged endurance exercise.