Venous Blood Acid-Base Status in Show Jumper Horses Subjected to Different Physical Exercises.

The aim of this study was to assess whether acid-base profile exhibits changes in regularly trained show jumping horses undergoing increasing exercise workloads. Seven female Italian saddle horses were subjected to three different physical exercise trials of increasing workload identified as three exercise phases (EPs). During EP horses were subjected to a standardized exercise test consisting of 15 minutes of treadmill, during EP horses were subjected to a show jumping test (height, 0.9-1.1 m; course length, 300 m), during EP horses underwent two jumping sessions carried out over two consecutive days. Blood samples were collected at rest (T), after exercise (T), and 30 minutes after the end of exercise (T). The values of pH, partial pressure of carbon dioxide (Pco), partial pressure of oxygen (Po), bicarbonate level (HCO), hemoglobin (Hb), and hematocrit (Hct) were measured. A significant effect of exercise workload and time (P < .001) on Po, Pco, HCO, Hb, and Hct values was found. The variation in the studied parameters resulted mostly reversible within T in horses when subjected to EP and EP, whereas Po, Hb, and Hct remained higher at T than T in horses when subjected to the second day of jumping section (EP) indicating a failure to recover. The results suggest that jumping sessions carried out over two consecutive days represent extra workload for horses, and this should be taken into account by veterinarian to prevent acid-base imbalance and for the maintenance of health and performance in equine athletes.