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“Bute – 5 mcg/ml . . . to be or not to be”

“Bute – 5 mcg/ml . . . to be or not to be”
By Kent H. Stirling, FHBPA Executive Director
August 11, 2010
Some 400 years later, I’m sure Shakespeare’s Prince Hamlet didn’t foresee his famous words being used in the topic of a panel discussion between those who advocate maintaining the phenylbutazone  threshold of 5 mcg/ml in the thoroughbred race horse and those that wish to see it lowered to 2 mcg/ml.
This forum held during the National HBPA Convention in Minneapolis on July 23rd was, if not one of the best ever hosted by the NHBPA, certainly the all time largest in number of panel members.  Ten panelists made their own presentations plus two other presentations for panelists unable to be present due to last minute emergencies.
The ten panelists and twelve presentations were split evenly between those wishing to see the threshold remain at 5 mcg/ml and those wishing to reduce it to 2 mcg/ml for the administration of bute at 24 hours prior to post time.
The supporters of the present 5 mcg/ml threshold were:
Dr. Steven Barker, Lab Director and State Chemist Louisiana State Racing Commission
Dr. George Maylin, Director New York State Wagering Board Drug Testing and Research Program.
Dr. Steven Selway, Equine Surgeon with clinics at Belmont and Gulfstream Park.
Dr. Dan Shields, Equine Practitioner in Southern California, founder and CEO of Statison Medical.
Dr. Thomas Tobin, Professor, Department of Veterinary Science, Gluck Equine Research Center.
Darrell Vienna, Trainer and attorney in Southern California, Vice President of the California Thoroughbred Trainers.
The proponents of reducing the bute threshold to 2 mcg/ml were:
Dr. Rick Arthur, Equine Medical Director, California Horse Racing Board, RMTC Secretary.
Matt Iuliano, Executive Director and Vice President of the Jockey Club.
Dr. Tom David, Equine Medical Director, Louisiana State Racing Commission.
Dr. Mary Scollay, Equine Medical Director, Kentucky Horse Racing Authority.
Dr. Lawrence Soma, Professor of Anesthesiology and Professor of Large Animal Veterinary Medicine, New Bolton, University of Pennsylvania.
Dr. Keith Soring, Director of Racing for Iowa Racing and Gaming Commission, previously an equine practitioner in the Midwest and Florida.
This important forum with a panel that was a virtual who’s who of racing medication, testing and regulations experts, unfortunately, got no media coverage with the exception of an article after the convention in the Thoroughbred Times which correctly quoted the HBPA press release, which stated in part:
” . . .  it is clear that the scientific community is not unanimous in its opinion that the preponderance of scientific evidence demonstrates that there is an effect on the athletic performance of the horse at the 5 mcg/ml regulatory threshold  . . . . It is understood that while the vast majority of horses test below the 2 mcg/ml level, the 5 mcg/ml level simply provides a safety margin to avoid inappropriate positives.”
This last part is important because no consideration was given at the RMTC for the horse who trains on bute pills then stops at 48 hours prior to post time and has an IV administration of bute at 24 hours prior to post time.  Since oral bute builds up in the horse’s system, this horse is very likely to go over the proposed 2 mcg/ml threshold.  Also remember the new level is the 2 mcg/ml not the 2.2 or 2.6 mcg/ml previously used by some supposed “2 mcg/ml states”.
With more bute overages to refer to as “positives”, the media will have a feeding frenzy and Congress will soon be inviting us back to discuss our ever increasing number of drug “positives.”
But let’s get back to the Thoroughbred Times online and hard copy articles which quoted little from the forum about studies on bute at both the 2 and 5 mcg/ml levels in the two states that had used both levels, Iowa and Virginia.  But both articles did quote Dr. Scot Waterman’s numbers presented a month previously at the “Welfare and Safety of the Racehorse Summit” from two unnamed states that showed a rather dramatic increase in catastrophic breakdowns at the 5 mcg/ml threshold.  The Thoroughbred Times hard copy, after quoting Dr. Waterman’s numbers in detail, did mention in passing that a study presented at the convention suggested there was no statistically significant change between the two levels.
The catastrophic breakdown numbers in one state (Virginia) according to Dr. Waterman went from “0.69 per 1,000 starts to 2.26 after the change” to 5 mcg/ml.  Unfortunately, Dr. Waterman must have stopped his 2 mcg/ml years at 2001 (Virginia has excellent records back to 1997 on catastrophic breakdowns) when there were no catastrophic breakdowns, as 2000 had 3 of them.  At least that is the only way I came up with numbers similar to Dr. Waterman’s.
When Dr. Tom Tobin did his study with Dr. Rich Harden, Virginia Racing Commission Equine Medical Director, they discovered that 2005, which had over 3,000 starts and just two catastrophic breakdowns, was actually run at the 5 mcg/ml threshold level and not the 2.6 mcg/ml level, and that that incorrect information had been given to Dr. Waterman.  This changed the numbers rather severely.  If one examines ’05 to ’08 which were run at 5 mcg/ml with ’03 and ’04 run at 2.6 mcg/ml and ’09 and ’10 at 2 mcg/ml you get two four year periods that show “no significant difference” in catastrophic breakdowns regardless of whatever statistical evaluation method (Fisher, ANOVA, etc.) is used.
In the unnamed state that turned out to be Iowa, Dr. Waterman correctly used the numbers that Dr. Soring’s presentation contained, which were that from 2000 to 2006 at 2.2 mcg/ml the catastrophic breakdowns were 1.31 per 1,000 starts, and from 2007 to 2009 at 5 mcg/ml it increased to 1.95 per 1,000 starts.  The year with the highest incidences of breakdowns was 2004 (2.2 mcg/ml) followed by 2009 (5 mcg/ml) with the next highest catastrophic breakdown numbers a dead heat between 2006 (2.2 mcg/ml) and 2008 (5 mcg/ml).
It was pointed out by a Racing Form chart caller and several trainers from Iowa in the audience that the racing surface there has had issues for the last decade.  In fact when Dr. Soring’s numbers were given to a statistician, the two lowest years of number of breakdowns were removed and again the data proved “no significant difference between 2.2 and 5 mcg/ml” using Fisher’s Extract test and the Negative Binomial Regression Model.
I don’t pretend to understand how any of these statistical evaluation tests work, but I do understand the phrase “no significant difference”.
A number of the other presentations, while very interesting, were heavily loaded with anecdotal information, but were short on science, except for the fact that the horse could be under a slight pharmacological effect from the bute at the time of the pre race veterinary examination.  But let’s look at Iowa’s time of pre-race inspection, usually between 7 and 9 a.m. Post time is 3:30 p.m. on weekdays and 6:30 p.m. on weekends.  Does anyone see a problem here?
Couldn’t that horse in a late race on the weekend actually end up being examined 14 or 15 hours before he runs, or just 9 or 10 hours after bute was administered?
Why not do something radical like move the pre race exam to 12 to 2 p.m. on weekdays and to 3-5 p.m. on weekends?
Is this really about the horse or the examining veterinarian?
For thirty years the 5 mcg/ml threshold has worked successfully, but now the Jockey Club and some Medical Directors want it changed, apparently with or without scientific evidence to support the change.  Why?
Fortunately this three hour forum was video taped and sent to the ARCI Model Rules Committee for their review and is available for anyone else who wants it.  Hopefully, ARCI will bounce the proposed 2 mcg/ml rule back to the RMTC for more adequate scientific evidence that proves a change to 2 mcg/ml is warranted.