RCI Approves Lower Bute Threshold

Newsdate: Mon, 25 Oct 2010 - 10:00 am
Location: LEXINGTON, Kentucky

On October 22, the Board of Directors of the Association of Racing Commissioners International (RCI) gave final approval to lower the allowable level of phenylbutazone. The board voted 16-0 in favor of lowering the threshold for penalty from 5 micrograms of phenylbutazone (bute) per milliliter of plasma or serum to 2 micrograms.

RCI President Ed Martin said “Absent a compelling and convincing medical reason to the contrary, the RCI has concluded that it is in the interest of the horse that the proposed change be adopted.”

He noted that RCI will now review the current penalty guidelines to address concerns that have been raised pertaining to potential first-time violations of the new rule.

RCI's Model Rules Committee, in supporting the change, recommended that jurisdictions work with local horseman's groups to transition to the new policy and consider a grace period so trainers can adjust.

The change to the Model Rule comes after months of research and discussion, beginning with the RCI Regulatory Veterinarian Committee, who voiced concerns that phenylbutazone could interfere with pre-race examinations due to the possibility of analgesic effects of the drug. RCI asked the Racing and Medication Testing Consortium (RMTC) to review the research on the topic, and the Scientific Advisory Committee of the RMTC voted without objection to support the lowering of the threshold.

The RCI Model Rules Committee had planned to vote on the matter during a spring meeting, but at the request of the National Horsemen’s Benevolent and Protective Association (HBPA) delayed that vote until after the topic could be discussed at its summer convention.

After considering alternate viewpoints expressed at the National HBPA meeting, the RCI Model Rules Committee voted in favor of lowering the threshold in September. The lowered threshold received formal support from groups such as the American Association of Equine Practitioners, The Jockey Club, The Jockeys’ Guild, and the Thoroughbred Owners and Breeders Association. The National HBPA, Thoroughbred Owners of California, and California Thoroughbred Trainers, representing the largest majority of horsemen racing in the United States, strongly opposed the change.

Because the proposed new racing regulatory compact is not yet in existence, the adoption of the model rule change, if it occurs, will occur in different jurisdictions at different times, as individual commissions commence formal rule making on an individual basis.

Additional Guidelines Issued

Based on the recommendation of its Scientific Advisory Committee, the Racing Medication and Testing Consortium (RMTC) board of directors has recommended scientifically identified withdrawal guidelines and plasma thresholds for the short-acting bronchodilator glycopyrrolate, the muscle relaxant methocarbamol and four anabolic steroids, three of which are endogenous (naturally occurring) in the horse. A recommendation for the non-steroidal anti-inflammatory medication firocoxib has also been approved pending resolution of one outstanding issue.

"Administration studies on these medications were developed and funded by the RMTC over the past few years in an effort to provide horsemen and practicing veterinarians with withdrawal guidelines that will enable the therapeutic use of these medications without compromising the integrity of racing competition or the welfare of our human and equine athletes," said Dr. Rick Arthur, chair of the RMTC Scientific Advisory Committee and equine medical director for the California Horse Racing Board.

"The results of these studies have been eagerly anticipated by the industry, and we will continue to conduct important research on other therapeutic medications that are commonly used in managing the health of racehorses."

The board made these recommendations at its meeting at the University of California-Davis on October 12. The specific recommendations are as follows:

• Glycopyrrolate: Threshold concentration of 3.5 picograms/ml. in serum or plasma, which regulates a 24-hour withdrawal guideline for a single, intravenous total dose of 1 mg.

• Methocarbamol: Threshold concentration of 1 nanogram/ml., which regulates a 48-hour withdrawal guideline for a single intravenous dose of 15 mg./kg.

• Firocoxib: Threshold concentration of 40 nanograms/ml. in serum or plasma, which regulates a seven-day withdrawal guideline when administered at the FDA-approved label dose, pending a review of clinical effects by the RMTC Scientific Advisory Committee.

• Boldenone: Screening limit no greater than 100 pg./ml. in serum or plasma with a confirmatory threshold no greater than 25 pg./ml. for all horses regardless of sex, which regulates an 82-day withdrawal time.

• Nandrolone: Screening limit no greater than 100 pg./ml. in serum or plasma with a confirmatory threshold no greater than 25 pg./ml. for geldings, fillies and mares, which regulates a 35-day withdrawal time. Male horses other than geldings will not be tested for nandrolone in blood.

• Stanozolol: Screening limit no greater than 100 pg./ml. in serum or plasma with a confirmatory threshold no greater than 25 pg./ml. for all horses regardless of sex, which regulates a 47-day withdrawal time.

• Testosterone: Screening limit no greater than 100 pg./ml. in serum or plasma with a confirmatory threshold no greater than 25 pg./ml. for geldings, fillies and mares and a confirmatory limit of 2 mcg./ml. for male horses other than geldings, which regulates a 30-day withdrawal time.

In addition, the RMTC board of directors approved a plasma threshold of 10 micrograms/ml. for DMSO, which would allow for the use of DMSO as a topical leg paint but would not allow for the oral or intravenous administration of the drug. The board also recommended that DMSO be reclassified by the RCI Drug Testing Standards and Practices Committee to a Class 4 substance when appearing in samples in excess of the threshold concentration.

Based on a report provided by the Scientific Advisory Committee, the RMTC board expects to be able to issue recommendations for acepromazine, pyrilamine, mepivacaine, lidocaine, procaine, and butorphanol at its next full meeting in March of 2011.

About the Author

Flossie Sellers

As an animal lover since childhood, Flossie was delighted when Mark, the CEO and developer of EquiMed asked her to join his team of contributors.

She enrolled in My Horse University at Michigan State and completed a number of courses in everything related to horse health, nutrition, diseases and conditions, medications, hoof and dental care, barn safety, and first aid.

Staying  up-to-date on the latest developments in horse care and equine health is now a habit, and she enjoys sharing a wealth of information with horse owners everywhere..