Evaluation of Cobalt as a Performance Enhancing Drug Study Results Published in Comparative Exercise Physiology

NEW BRUNSWICK, N.J. In a joint project by the Equine Science Center at Rutgers University;  Equine Integrated Medicine, Georgetown, Kentucky; Duer Forensic Toxicology, Clearwater Florida; and the New York Drug Testing and Research Program, Morrisville State College a recently published journal article shows that a sterile solution of cobalt salts (50 mg of elemental cobalt as CoCl2 in 10 ml of saline, given IV for three consecutive days) did not affect aerobic or anaerobic performance or plasma erythropoeitin concentration in race fit Standardbred horses.   

“The Evaluation of Cobalt as a Performance Enhancing Drug (PED) in Racehorses” study sought to determine if cobalt acts as a performance enhancing drug by altering biochemical parameters related to red blood cell production, as well as markers of aerobic and anaerobic exercise performance.  The study also identified the normal distribution of plasma cobalt in a population of horses on a maintenance dietary ration without excessive cobalt supplementation. Research was conducted using 245 Standardbred horses with no supplementation of cobalt from farms in New York and New Jersey, including those at the Rutgers University Equine Science Center.  The authors concluded that a threshold of 25 micrograms per liter in plasma, currently in place in many racing jurisdictions, may result in horses exceeding the threshold without excessive cobalt administration. They suggest that a threshold of 71 micrograms per liter be considered. 

The study also found that plasma cobalt concentrations over 300 ppb had no adverse effects on horse well-being or on performance.  However, we caution that investigators have found that higher doses are purportedly being illicitly administered to horses with reported dangerous adverse and life-threatening effects on the horses.  The present study does not address the effects of administering the much larger doses that racing officials and investigators have suggested are being misused to enhance performance.   

According to Dr. Kenneth H. McKeever, Associate Director for Research at the Equine Science Center,The results of this study are the first to document that administration of cobalt salts at the level studied does not stimulate the production of red blood cells and does not affect markers of performance in race fit horses. Horses appear to respond in a species-specific fashion that is different from human studies that showed toxicity at plasma concentrations above 300 ppb. This study presents data rather than speculation for the decision-making process for setting thresholds. 

The study has been published as an open access paper, accessible for free at: https://www.wageningenacademic.com/doi/abs/10.3920/CEP200001 

 The study was funded in part by the United States Trotting Association.