A recent Racing Medication and Testing Consortium review of violation records from nine states that lowered their phenylbutazone threshold from five micograms per milliliter of plasma to the RMTC-recommended level of two micrograms reveals that fewer overages of the medication are occurring at the lower threshold.
Phenylbutazone is a non-steroidal anti-inflammatory medication. In most states, one non-steroidal anti-inflammatory may be administered 24 hours prior to racing to decrease inflammation and provide pain relief. In 2009, the phenylbutazone threshold was brought before the RMTC board by regulatory veterinarians who expressed concern that the medication, at the five microgram per milliliter threshold, could be hiding lameness and compromising pre-race examinations.
The regulatory veterinarians' concerns were confirmed by Dr. Larry Soma at the University of Pennsylvania. His 2010 review of 120 research papers on phenylbutazone, which was published in 2012, confirmed that lameness and inflammation could be altered by the presence of phenylbutazone at the five-microgram threshold at 24 hours. In response, the RMTC lowered the phenylbutazone recommended threshold to two micrograms in 2010.
The Association of Racing Commissioners International (RCI) provided records from the racing commissions of California, Florida, New Mexico, New York, Ohio, Pennsylvania, and Virginia—all of which have lowered their phenylbutazone threshold from five micrograms to two micrograms in recent years. The New Jersey Racing Commission and the Indiana Horse Racing Commissions provided records directly to the RMTC.
The records revealed that in the nine states, trainers had amassed a total of 41 phenylbutazone threshold violations in the six months of racing prior to enacting the lower threshold. The highest reported value with the higher threshold was over 29 micrograms per milliliter of plasma.
In those same states, in the six months of racing after the lower threshold was adopted, there were a total of 23 phenylbutazone threshold violations. The highest reported value under the lower threshold was just over 8 micrograms.
RMTC Executive Director Dr. Dionne Benson believes the data clearly demonstrate the two-microgram threshold is a workable level for horsemen.
"Trainers saw a 44% decrease in violations and regulatory veterinarians are better able to evaluate the horses," she said. "Overall, this change improves the safety and welfare of horses and jockeys."
To date, there are 15 racing U.S. jurisdictions that have adopted a two-microgram threshold.
The data for Kentucky, Arkansas, Illinois, and Texas was not included as those jurisdictions have not yet held six months of racing under the new threshold.
The remaining jurisdictions not represented in the RMTC's review had an original threshold which was lower (2.5 micrograms in Delaware and two micrograms in Maryland).
"Conducting research and then developing and recommending uniform policies have been integral components of the RMTC mission since it was established," Benson said. "The findings from this review prove that our system is working and that we can continue to take steps to ensure the health and welfare of the racehorse and the integrity of our sport."