Exercise-Induced Acid-Base, Electrolyte, and Metabolic Responses in Colombian Creole Horses Across Different Gait Modalities.

Overview

• This study investigated how exercise affects blood chemistry in Colombian Creole Horses (CCHs), focusing on acid-base balance, electrolytes, and metabolic markers.
• It examined whether these changes vary by sex, geographic origin, or the horses’ gait type during exercise.

Introduction and Purpose

• Colombian Creole Horses are widely used in various athletic activities, but their physiological responses to exercise are not well understood.
• The study aimed to characterize changes in blood biochemical and gas parameters caused by exercise.
• It also sought to determine if these changes differed based on
• Sex (male vs. female)
• Geographic origin (different regions within Colombia)
• Gait modality (types of movement patterns during exercise)

Methods

• Design: Analytical observational study with repeated measures
• Subjects: 76 athletic Colombian Creole Horses
• Sample Collection: Blood samples drawn from the jugular vein at two time points:
• At rest (pre-exercise)
• Immediately after exercise
• Parameters Measured:
• Acid-base indicators — pH, partial pressure of carbon dioxide (pCO2), bicarbonate (HCO3-)
• Electrolytes — sodium (Na+), potassium (K+), calcium (Ca2+), chloride (Cl-)
• Metabolic markers — glucose, lactate, creatinine
• Analysis: Compared within-subject changes pre- and post-exercise and conducted subgroup analyses by sex, geography, and gait type

Key Findings

• Exercise produced physiologically expected changes in blood chemistry:
• pH decreased slightly by 0.01 units, indicating a mild acidification of blood.
• Carbon dioxide pressure dropped by 2.39 mmHg.
• Bicarbonate levels decreased by 1.7 mmol/L.
• Lactate rose by 2.96 mmol/L, indicating increased anaerobic metabolism during exercise.
• Additional metabolic responses included modest increases in glucose and creatinine concentrations.
• Electrolyte concentrations (sodium, potassium, calcium, chloride) remained mostly stable, showing minimal alteration due to exercise.
• Sex and geographic origin did not significantly affect the biochemical response to exercise.
• Gait modality was a notable factor influencing acid-base responses, with certain gait types showing greater decreases in carbon dioxide pressure and bicarbonate.

Interpretation and Implications

• The observed blood chemistry changes reflect a mild exercise-induced metabolic acidosis:
• Lower pH and bicarbonate and elevated lactate are consistent with lactic acid buildup and buffering during anaerobic activity.
• Decreased carbon dioxide pressure suggests respiratory compensation to maintain acid-base balance.
• Stable electrolyte levels imply that the exercise intensity or duration did not create significant electrolyte disturbances in these horses.
• The lack of sex or geographic differences suggests uniform physiological responses across these demographic factors within the breed.
• The influence of gait modality indicates that how horses move during exercise affects the magnitude of acid-base changes, possibly linked to differences in metabolic demand between gait types.
• These findings help to better understand the physiological adaptations of Colombian Creole Horses to exercise, informing training, health monitoring, and performance optimization specific to gait types.

Summary

• This study provides the first detailed evaluation of blood acid-base, electrolyte, and metabolic responses to exercise in Colombian Creole Horses.
• It demonstrates a consistent mild metabolic acidosis with exercise, modulated by gait but not by sex or region.
• The results contribute valuable information for veterinarians, trainers, and researchers working with this important equine breed.