Electrolyte vs. glucose-electrolyte isotonic solutions for oral rehydration therapy in horses.

The research compares the effectiveness of an isotonic electrolyte solution designed to resemble equine sweat to that of an isotonic glucose-glycine-electrolyte solution for rehydrating exercising horses. The isotonic sweat-like electrolyte solution demonstrated a faster recovery of fluid and plasma electrolyte balances, making it the most effective solution tested.

Study Design and Methodology

• The researchers used ten horses in the study. The horses were dehydrated using frusemide, a medication often used as a diuretic, forcing the horses to lose fluids.
• These horses were then randomly allocated different rehydration solutions: an isotonic sweat-like electrolyte solution, a half-strength hypotonic electrolyte solution, an isotonic glucose-glycine-electrolyte solution, or plain water.
• Each solution was administered to the horses via a nasogastric tube and the volume of fluid provided was equivalent to the body weight lost by each horse due to dehydration.
• The researchers took blood samples both before and during a 6-hour rehydration period to monitor changes in the horses’ hydration and electrolyte levels.

Results and Findings

• All four solutions helped the horses recover their pre-frusemide levels of packed cell volume (PCV) and total plasma protein (TP) at similar rates. These parameters are used as indicators of the horse’s hydration status.
• The use of the isotonic sweat-like solution resulted in no changes to sodium (Na+) levels during rehydration. However, when other solutions were given, particularly the hypotonic solution and water, the horses showed significant reductions in sodium levels (hyponatraemia).
• Osmolality, a measure of solute concentration, remained stable when the isotonic solutions were given but decreased significantly when either hypotonic solution or water was used.
• The isotonic sweat-like solution was also seen to help plasma chloride (Cl-), potassium (K+) and creatinine levels return to premedication values significantly faster than the other three solutions.
• In conclusion, the isotonic sweat-like electrolyte solution outperformed the other solutions by swiftly restoring fluid and electrolyte imbalances; on the other hand, the isotonic glucose-glycine-electrolyte solution seemingly worsened the electrolyte imbalances in the studied horses.