This past year, horse racing regulators worldwide, most recently in Australia, have turned their attention to an unexpected substance: cobalt. Every horse needs this important element to survive, but some horsemen believe that supplementing the substance will help their horses gain a competitive advantage on the race track.
Cobalt is a trace mineral found in B vitamins that horses require in tiny amounts for correct functioning of their physiology. As a result, all horses will have trace amounts of the substance in their systems. (Humans also need cobalt in B vitamins with dietary sources including meat, liver, kidney, clams, oysters, milk, ocean fish and sea vegetables such as seaweed.)
Doctors have used cobalt to treat anaemia (essentially by increasing the blood’s oxygen-carrying capacity) in humans for decades. However, it was associated with a variety of adverse effects, including gastrointestinal, neurologic, cardiovascular, and thyroid problems. As a result, doctors have largely ceased using it. Some athletes, however, continue using it as a doping agent.
Until recently, researchers had not evaluated cobalt supplements’ beneficial or adverse effects in horses. Nevertheless, as racing regulators’ interest in the element has increased, so has the amount of research.
Last October, Indiana set a race-day cobalt threshold of 25 ppb for horses in that state. Doctors stated that prior to the threshold’s implementation, 6 to 7% of horses tested had increased cobalt levels. Since implementation, less than 1% of horses tested have had increased cobalt levels.
Kentucky is currently doing cobalt surveillance. The Racing Medication and Testing Consortium had not yet recommended a threshold value at the time of this presentation, but should soon.
Several additional studies assessing cobalt’s adverse effects, the administration of cobalt-containing supplements and blood samples from non-racing Standardbreds are underway. Thus, there is work underway evaluating different cobalt testing methods, which can result in different test outcomes.
In closing, doctors stress that while illicit cobalt use appears to be prevalent, it’s effects— whether these are negative or positive—aren’t currently well-understood with no one having documented any beneficial effects scientifically yet in horses.