Physiological Adaptation of Horses to High-Intensity Exercise During Polo Season in Kaduna State

Performance horses used in polo are subject to intense physical demands that elicit significant cardiorespiratory, haematological, and metabolic adaptations. Understanding these adaptations is essential for optimising training programmes, ensuring equine welfare, and reducing exercise-associated illness in polo horses maintained in Nigeria. This study characterised physiological responses to high-intensity exercise during the polo season in horses stabled at the Kaduna Polo Club, North West Nigeria. Thirty polo ponies were evaluated at three time points: pre-season, mid-season, and end of season. Parameters measured included resting and post-exercise heart rate, respiratory rate, rectal temperature, and recovery time. Blood samples were collected at rest and 30 minutes post-exercise for analysis of packed cell volume, lactate, creatine kinase, and aspartate aminotransferase. Urinalysis was performed for myoglobinuria detection. Post-exercise heart rate declined significantly from pre-season to end of season, reflecting cardiovascular conditioning. Post-exercise lactate concentrations were highest at mid-season, peaking at 9.4 mmol/L during intense chukka play. Creatine kinase and aspartate aminotransferase were significantly elevated above reference ranges in 23.3 percent of horses at mid-season, suggesting muscle stress. Myoglobinuria was not detected in any samples. Pre-season body condition score correlated positively with end-of-season cardiovascular recovery time. These findings provide practical physiological monitoring data relevant to polo horse management in Kaduna and support the use of serial biochemical monitoring as part of equine sports medicine programmes in Nigerian polo clubs. Keywords: polo horse, exercise physiology, creatine kinase, Kaduna, adaptation.