Metabolic causes of equine exercise intolerance

Area of Science:

• Equine exercise physiology
• Veterinary internal medicine

Background:

• Metabolic causes of exercise intolerance in horses are often subtle and challenging to diagnose.
• Increased metabolic demands during exercise can lead to muscle abnormalities, including exertional rhabdomyolysis (ER).
• Recent research is uncovering new causes of ER and highlighting the impact of endocrine disorders on equine performance.

Purpose of the Study:

• To summarize current knowledge on muscular and endocrine causes of exercise intolerance in horses.
• To discuss the cumulative effects of metabolic issues in heat exhaustion and outline management strategies.
• To review the efficacy and limitations of ergogenic aids in equine athletes.

Main Methods:

• Literature review of recent research on equine exercise intolerance.
• Synthesis of findings related to muscular causes, endocrine disorders (hypothyroidism), and heat exhaustion.
• Evaluation of proposed ergogenic aids for performance enhancement in horses.

Main Results:

• New causes of exertional rhabdomyolysis (ER) are being identified, with a focus on muscular origins.
• Hypothyroidism has been shown to negatively impact exercise tolerance in horses.
• Heat exhaustion management involves veterinary monitoring, cold water bathing, and fluid/electrolyte replacement; ergogenic aids have limited proven benefits.

Conclusions:

• Metabolic and endocrine factors significantly influence exercise intolerance in horses.
• Early veterinary monitoring and appropriate management are key for conditions like heat exhaustion.
• The effectiveness of ergogenic aids for improving equine performance remains largely unproven.