Pre-Ride Biomarkers and Endurance Horse Welfare: Analyzing the Impact of the Elimination of Superoxide Dismutase, δ-Aminolevulinic-Dehydratase, Thiobarbituric Acid Reactive Substances, Iron, and Serum Amyloid A Levels in Elite 160 km Endurance Rides

Abstract

High elimination rates and concerns for horse welfare are important issues in endurance riding. Improved understanding of the causes of elimination could increase completion rates in this sport. We have identified pre-ride laboratory risk factors that enable an assessment of potential elimination before the ride. A longitudinal cohort study was performed among 49 healthy horses competing in the 160 km endurance ride at the 2016 World Championship of Endurance Riding in Samorin/Slovakia. Blood samples were taken before the event. For statistical evaluation, horses were categorized into three groups: finishers, lame horses, and metabolically eliminated horses. Risk factors were calculated for each group using multinominal logistic regression. δ-Aminolevulinic-dehydratase (ALAD), thiobarbituric acid reactive substances (TBARSs), iron, and serum amyloid A (SAA) were measured and did not show an impact on the race outcome, but elevated pre-ride superoxide dismutase (SOD) was shown to have an effect on lameness elimination (p = 0.011). It might serve as an indicator for withdrawing horses at risk of later elimination before endurance rides, ultimately resulting in lower elimination rates and an increase in overall horse welfare.

Blood‐based assessment of oxidative stress, inflammation, endocrine and metabolic adaptations in eventing horses accounting for plasma volume shift after exercise

“…We therefore agree with Bollinger et al. (2023) that a low pre‐ride SOD is beneficial over a high pre‐ride SOD, whereby pre‐exercise nutritional supplementation could be influential.…”

“…In general, the findings of our study are consistent with other studies on eventing horses (Williams, 2016). Our results further support the view of Bollinger et al (2023) that elevated SOD could be an indicator of antioxidative capacity already being used (e.g. due to insufficient recovery) and not that there is plenty of antioxidant capacity left.…”

“…due to insufficient recovery) and not that there is plenty of antioxidant capacity left. We therefore agree with Bollinger et al (2023) that a low preride SOD is beneficial over a high pre-ride SOD, whereby pre-exercise nutritional supplementation could be influential.…”

“…However, this does not indicate that there is a discrepancy between ROS production and antioxidant systems, which could constitute pathological oxidative stress (Williams & Burk, 2012). But as ROS are difficult to measure due to their short half‐lives, metabolic products and cofactors must be used for measurement (Bollinger et al., 2023). Possible reasons for ROS production are increased oxygen consumption and mechanical muscle stress (Williams & Burk, 2012).…”