Horse Electrolytes and Recovery Science

Understanding the science of electrolyte replacement in horses enables more effective welfare management during exercise, heat, and recovery.

Key Facts

A horse in heavy work can lose 10-15 litres of sweat per hour, containing significant concentrations of sodium, chloride, and potassium
Hyponatraemia from electrolyte loss impairs neuromuscular function, contributing to muscle weakness and fatigue
Oral electrolyte supplements are most effective when given with access to fresh water — electrolytes without water worsen dehydration
Horses with thumps (synchronous diaphragmatic flutter) have calcium and magnesium deficiency requiring targeted IV supplementation
Commercial oral electrolyte pastes vary significantly in composition — products providing sodium and chloride at physiological ratios are most effective

Welfare Considerations

Electrolyte management is a critical welfare competency for owners of competition, endurance, and working horses. Under-replacement leads to fatigue, muscle dysfunction, and thumps. Over-supplementation or administration without adequate water causes hypernatraemia. The welfare goal is to match replacement precisely to loss, which requires understanding the horse's workload, sweat rate, and individual response to supplementation.

What You Can Do

Ensure horses have constant access to fresh water during and after exercise — electrolytes must always be paired with water
Use appropriate electrolyte formulations for your horse's workload and sweat rate
Learn to recognise thumps — the distinctive flank twitch — as a sign requiring veterinary assessment and IV electrolyte therapy
Develop a competition-specific electrolyte plan with your vet for horses in demanding disciplines