Fluid and electrolyte balance in endurance horses

Area of Science:

• Equine Sports Medicine
• Animal Physiology
• Exercise Science

Background:

• Horses experience significant fluid and electrolyte loss during endurance exercise, especially in hot conditions.
• Sweat is hypertonic, causing substantial loss of sodium, chloride, and potassium.
• Elevated plasma protein concentration in horses may indicate severe dehydration and impaired fluid shifts.

Purpose of the Study:

• To highlight the risks of dehydration and electrolyte imbalances in endurance horses.
• To explain the physiological basis for fluid loss and its consequences.
• To emphasize the role of veterinary examination in early detection.

Main Methods:

• Review of physiological responses during equine endurance exercise.
• Analysis of sweat composition and its relation to plasma.
• Observation of clinical signs associated with dehydration and exhaustive syndrome.

Main Results:

• Fluid losses can reach 10-15 liters per hour under strenuous conditions.
• Hypertonic sweat leads to significant electrolyte depletion (sodium, chloride, potassium).
• Increased plasma protein concentration is a marker for severe dehydration and intracellular fluid shift failure.

Conclusions:

• Dehydration and electrolyte imbalances are critical concerns in equine endurance sports.
• Early recognition of these issues by veterinarians is crucial for horse welfare.
• Physical examination is key to identifying dehydration and preventing exercise-induced exhaustion.