Towards the elimination of excessive cobalt supplementation in racing horses: A pharmacological review.

This research article reviews the effects of cobalt supplementation in racing horses, providing a background on its physiological benefits and harms while acknowledging the scarcity of specific data for horses. It points to a need for more research to define optimal threshold levels and supplement regimens for cobalt in racing horses, highlighting welfare and performance concerns.

Key points of the research

• This article provides a review of the role and impacts of cobalt in racehorses. The researchers underscore cobalt’s essential role in equine health and performance as it increases the production of red blood cells, enhancing aerobic performance. However, excessive cobalt use can lead to significant health risks, such as cardiovascular, haematological, thyroid gland and reproductive toxicity.
• The article discusses the lack of definitive, horse-specific data and research on the effects of cobalt. Existing pharmacokinetic data, however, reveals that intravenously administered cobalt in horses takes a long time to eliminate and can accumulate in tissues over time.
• Given the evidence and current lack of specific thresholds, the authors discuss and recommend specific plasma and urine cobalt concentration levels as potential thresholds. At the same time, they note that this isn’t an established supplementation regimen, and further research and testing need to be carried out to fully establish these thresholds’ impacts.
• Overall, the paper’s purpose is to identify gaps in the current understanding of cobalt supplementation in racehorses and to propose areas for future research, enabling the determination of safe and effective cobalt thresholds.

Limitations and recommendations for future research

• One of the main limitations highlighted in this paper is the significant lack of equine-specific data regarding the adverse effects and optimal dosage levels of cobalt. Most existing studies extrapolate from data based on laboratory animals and humans, but species-specific data is needed to establish reliable and safe cobalt supplementation guidelines for racehorses.
• The authors of the study recommend investigating and characterising the potential adverse effects of cobalt at the proposed threshold levels. They believe this is crucial for defining a supplementation regimen and better understanding cobalt’s impacts on horse health and performance.
• The researchers also suggest longitudinal studies to longitudinally examine cobalt’s accumulation in equine tissues and the long-term impact on equine health. This could help shape more precise and effective cobalt supplement regimens for racehorses.