Corticosteroids in Racehorses: Beneficial But Controversial

Corticosteroids in Racehorses: Beneficial But Controversial

Corticosteroid use is controversial, but the medications are beneficial when used appropriately, one vet says.

Photo: The Horse Staff

The use of corticosteroids in racehorses has created controversy, but the medications are beneficial when used appropriately. That was the message delivered by Wayne McIlwraith, BVSc, PhD, FRCVS, Dipl. ACVS, Dipl. ECVS, during the Welfare and Safety of the Racehorse Summit IV, held Oct. 16-17 at Keeneland Race Course in Lexington, Ky.

"Proponents, of course, will say they (corticosteroids) are needed to decrease inflammation, musculoskeletal pain, ongoing joint degradation, and opposite limb overload," said McIlwraith during his presentation on the summit's opening day. "The opponents will say they are merely masking pain and lead to joint deterioration. I'm obviously in the first camp, the proponents of corticosteroids. They have a substantial place in the practice of veterinary medicine. But there are side effects with some products. Not all corticosteroids are the same."

McIlwraith's talk included a review of research on corticosteroids.

"Depo-Medrol (methylprednisolone acetate) reduces lameness, but also causes a significant increase in cartilage degradation," he said. "That problem isn't seen with other products such as Vetalog (triamcinolone acetonide) and Celestone Soluspan (betamethasone sodium phosphate and betamethasone acetate).

"Depo-Medrol is bad; the others are good. That's the bottom line," said McIlwraith, who is based at Colorado State University and is a pioneer in the field of equine orthopedic research and surgery.

Veterinarians administer corticosteroids to racehorses most commonly through intra-articular (in the joint) injections. This group of medications is potent and long-lasting, which raises regulatory issues.

"That is hugely important when we start discussing the need for the use of them very close to competition," McIlwraith said. "There needs to be a point where therapy ends and competition begins. That is part of the dilemma we have."

The New York State Racing and Wagering Board recently enacted a series of new medication rules based on recommendations from a task force on racehorse health and safety. Under those rules, the administration of corticosteroids systemically is prohibited within five days of a race. The medications also can't be injected into a horse's joints within seven days of a race. In addition, intra-articular Depo-Medrol can't be given within 15 days of a race.

McIlwraith suggested following his talk that regulators should be even stricter.

"At the moment, they're saying seven days, but you could make it 14 days without a problem for the so-called shorter-acting corticosteroids because they are still effective (therapeutically)," he said. "You would take away all those concerns about a horse being blocked (from feeling pain) and that kind of thing."

About the Author

Deirdre Biles

Deirdre Biles is the Bloodstock Sales Editor for The Blood-Horse magazine.

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