Traditional and quantitative analysis of acid-base and electrolyte imbalances in horses competing in cross-country competitions at 2-star to 5-star level.
Authors: Kirsch Katharina, Sandersen Charlotte
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Maintaining optimal acid-base and electrolyte homeostasis is fundamental to equine athletic performance and post-competition recovery, yet the physiological responses to cross-country eventing across different competitive levels remain incompletely characterised. Kirsch and Sandersen collected jugular venous blood samples from 38 event horses before and after cross-country tests at 25 competitions (2-star to 5-star level), analysing traditional acid-base parameters alongside quantitative strong ion modelling to compare diagnostic approaches. Both methods revealed significant postexercise changes—notably decreased pH, chloride, and bicarbonate alongside elevated potassium and lactate—with the magnitude of these alterations correlating with competition intensity. Crucially, the strong ion difference approach identified metabolic acidosis in a substantially higher proportion of horses than traditional blood gas interpretation alone, suggesting that conventional analysis may underestimate the true extent of acid-base derangement in cross-country athletes. For practitioners managing eventing horses, these findings underscore the importance of interpreting postexercise blood parameters through quantitative methods when assessing recovery status and informing post-competition electrolyte replacement strategies, particularly at higher competition levels where physiological demands are most pronounced.
Read the full abstract on PubMed
Practical Takeaways
- •Event horses show predictable acid-base and electrolyte shifts during cross-country; more severe changes occur at higher competition levels, suggesting tailored management strategies based on event difficulty
- •Traditional blood gas interpretation may underdiagnose postexercise metabolic acidosis in event horses; quantitative analysis provides clinically useful detail for monitoring performance horses
- •Electrolyte monitoring (particularly potassium and chloride changes) should be part of postexercise assessment in eventing horses to guide rehydration and recovery strategies
Key Findings
- •Postexercise blood samples showed significant decreases in pH, chloride, and bicarbonate with increases in potassium across 38 eventing horses
- •Quantitative strong ion approach identified metabolic acidosis in a higher proportion of horses compared to traditional acid-base analysis methods
- •Acid-base parameter changes were significantly affected by competition level, with differences between 2-star to 5-star events
- •Strong ion gap and total nonvolatile weak buffer concentration increased postexercise, indicating complex multifactorial acid-base changes