Commentary: Give Bute the Boot

Few issues in horse racing fire up people's emotions like medication. A couple of years ago the target was anabolic steroids, and the industry reacted quickly. By Jan. 1, 2009, most U.S. racing jurisdictions had adopted rules banning the use of anabolic steroids.

Today the target is phenylbutazone, an analgesic non-steroidal anti-inflammatory more commonly known as Bute. Think Advil for horses.

The Model Rules Committee of the Association of Racing Commissioners International voted 12-0 (with one abstention) to lower the level of race-day Bute from 5 micrograms per milliliter to 2 micrograms. What is driving the proposed change is a concern that horses unfit to race are slipping past the pre-race veterinary exam because Bute is masking various problems. Rick Arthur, DVM, equine medical director for the California Horse Racing Board, noted in a speech at The Jockey Club Round Table in August that 90% of all horses that suffer fatal musculoskeletal injuries have some pre-existing injury at the site of the fatal injury.

Lowering the threshold to 2 μ/ml (micrograms/milliliter) may allow the veterinarians conducting pre-race inspections to do their jobs better and avoid catastrophic breakdowns. That's the goal.

The proposed rule change, however, has some problems, according to members of the National Horsemen's Benevolent and Protective Association, the Thoroughbred Owners of California, and the California Thoroughbred Trainers. The biggest problem is little or no research exists as it relates to the rule change, even though decades of research have been conducted on how Bute works inside a horse. Will lowering the amount of Bute alone affect pre-race exams or are other drugs involved? Does the drop from 5 μ/ml to 2 μ/ml improve the identification of horses that should not be starting in a race? Anecdotal evidence from some racetrack veterinarians suggests Bute is a factor, but this is not the same as research.

"We supported full force the anabolic steroid rule change," said Joe Santanna, president and CEO of the National HBPA. "Show us the scientific evidence, and if it is just like the anabolic steroid issue, we're in."

Calling for more research is seen as stonewalling by the ARCI, Racing Medication and Testing Consortium, and The Jockey Club.

Scot Waterman, RMTC executive director, said no medication used in horses has been studied more than Bute, and the research indicates a single 2-gram intravenous injection could be administered less than 24 hours before a race and not be detected postrace at the current 5 μ/ml level. Intravenous Bute moves out of the horse's system more quickly than paste Bute. "You could come in at 15, even 12 hours (before a race) and still be less than 5 micrograms postrace," he said.

No one questions the need to keep horses sound and to catch cheaters, but there are some questions about the proposed rule change.

First, the rule change does not address two other commonly used non-steroidal anti-inflammatory drugs that function like Bute: flunixin and ketoprofen. Why single out one medication? Arthur said these medications are not included because the permitted threshold is too low already. A trainer could give them at the dosage required to be effective 24 hours from a race and beat the test. On the other hand, the permissible level for Bute does allow the opportunity for it to be given within 24 hours of a race. One researcher admitted the 5 μg/ml level was "generous."

Another issue is the drop to 2 μ/ml, which according to research allows no safety margin. A report on medication recommendations submitted in September to the Pennsylvania Horse Racing Commission showed that 20 horses given 2 grams of Bute intravenously had plasma concentrations ranging from 0.5 μ/ml to 2.1 μ/ml. That means even if the 24-hour rule is followed, 5% (1 of 20, according to the study) of the horses given Bute according to the guidelines could wind up with a positive test. If racetracks suddenly see a spike in Bute positives with trainers getting fined and suspended, is that good for the sport and has it protected any horses? You could argue the average sports fan doesn't distinguish between Bute and steroids when hearing about drug positives in horse racing. A drug positive is seen as cheating. Arthur said the predicted rash of positives is unlikely because a margin of error is built into the testing. No one is getting a positive for a 2.1 μ/ml test result. In California, for example, the lowest Bute positive is 5.29 μ/ml.

There would be changes in when and how much Bute could be given with the rule change. For the lower threshold to work, horsemen would have to give 2 grams of Bute 36 hours before a race or give only 1 gram of Bute 24 hours out, according to Larry Soma, VMD, of the University of Pennsylvania's School of Veterinary Medicine, who did the research review for the RMTC.

Without question, Bute and other NASAIDs help horses in training. But do we really need them on race day? Most vets will say it's better to give a horse time off rather than medication. It also seems odd for the U.S. racing industry to fight over a difference of 3 μ/ml when the rest of the world sets its raceday standard for Bute at zero. There are differences between European and American racing. Europe has mostly turf races, fewer starts, and scaled-back winter flat racing. Australia does race year-round, however, and the collective rate of catastrophic breakdowns in the major European racing countries and Australia is 0.6 per 1,000 starts. In the U.S. it's 2 per 1,000 starts. We allow medication on race day. Other countries don't.

It appears the time has come, for the good of the horse, to scrutinize our own racing calendar, stop squabbling over a few micrograms, and push the permissible level of Bute to zero.

(Originally published on

To comment on this editorial, visit Eric's blog.

About the Author

Eric Mitchell

Eric Mitchell is a Editorial Director and Editor-in-Chief The Blood-Horse magazine.

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