Mid-Atlantic interests pushing bisphosphonates ban

Thoroughbred constituencies and racing regulators in the mid-Atlantic region are united behind an effort to ban the use of bisphosphonates in horses younger than 4 years old and will push national organizations to adopt rules prohibiting off-label use of the drugs over the next few months, the groups said.

The position staked out by the constituencies, which include groups in Delaware, Maryland, New Jersey, New York, Virginia, and West Virginia, coincides with an urgent review of Thoroughbred medication practices taking place within the racing industry in the wake of a spate of deaths at Santa Anita Racetrack in Southern California that has led to widespread criticism of racing. Because bisphosphonates can have both positive and negative effects on bone remodeling and growth, the drugs have become a prime target for concern in an industry in which breakdowns have once again leapt to the fore.

Bisphosphonates, which are used in humans to treat osteoporosis, are approved for use in horses 4 years old or older to treat navicular disease, an inflammatory disease affecting a bone in the hoof, but reports of off-label use of the drugs surfaced within the past 10 years. Those reports generally focused on breeders and consignors who were allegedly using the drugs in young horses in order to build bone strength prior to the horses going through the auction ring.

On Monday, North America’s three major auction companies – Keeneland, Fasig-Tipton, and Ocala Breeders Sales Company – announced a new policy that will allow buyers to have horses younger than 4 years old tested for bisphosphonates. If the test result is positive, the buyer will be allowed to return the horse to the consignor.

The mid-Atlantic groups have said that they support the adoption of an industrywide model rule banning the use of the drugs for any administration other than the approved use. The Association of Racing Commissioners International, which drafts and approves model rules, is scheduled to meet April 2-5 in Arcadia, the home of Santa Anita Park, and the head of the Maryland Racing Commission, Mike Hopkins, said he expects to push for the adoption of a model rule at that meeting. Hopkins is also the current chairman of the ARCI.

“The regulatory community strongly supports this action and will take the necessary steps to see that it is enforced,” Hopkins said.

While there have been anecdotal reports of bisphosphonate use within the racing industry for at least the last five years, there is no clear data on how widespread administrations may be or what dosage or regimen administrators are using. The drugs have long-lasting impacts on bone by “sequestering” in bone tissue, only to be activated when the bone goes through a remodeling stage, and notes on the use of the drugs produced by the FDA stress that the “safe use” of either of the two drugs on the market “has not been evaluated in horses less than 4 years of age.” The FDA notes also state that “because bisphosphonates inhibit osteoclast activity and decrease bone turnover, these drugs may affect bone growth.”

A leading cause of catastrophic injury in horses has been identified as existing damage to bone at the microscopic level, so it’s not surprising to find that the racing industry’s attention has landed on the drugs at a time of increased concern over breakdowns.

But there’s a political component to the attention as well. In the past, breeders have been outspoken about alleged drug transgressions by trainers and have mostly aligned themselves with efforts to ban the raceday use of the diuretic Lasix to treat bleeding in the lungs, a proposition opposed by most rank-and-file trainers. That has led to a deepening rift between breeders and trainers over drug regulations, and many horsemen’s organizations are not unhappy to point a finger at practices thought to be mostly predominant in the breeding and sales community, which do not face anything near the amount of daily regulation or drug testing as the racing community.

The sales company testing policy, which will go into effect on July 1, will require the buyer of a horse to pay for the test to detect bisphosphonates, at $500 for each test. If the horse does test positive, the cost will then be transferred to the consignor, the sales companies said.

Current tests for bisphosphonates are “based on published results that have been out there for years,” according to Dionne Benson, an equine veterinarian who is the head of the Racing Medication and Testing Consortium, an industry-funded group that recommends medication policies for horse racing. The tests can accurately detect both of the drugs on the market, Benson said, but they are also based on methodologies that are outside the normal drug-testing protocols for medications, leading to the relatively high cost of the tests.

The tests can detect the drug at a limit of perhaps 100 days outside of administration, but the efficacy of the drugs can last for years, Benson said, because of the way the drugs reside in bone tissue. So tests to detect the drugs may not identify horses that were once administered them early in their lives or careers.

“They’re challenging drugs in a lot of ways,” Benson said.

The RMTC identified bisphosphonates as an issue of concern three years ago, but it has not yet received research proposals that have sought to answer the most pressing questions about their impacts, according to Benson. As a result, the RMTC formed a working group earlier this year to identify which questions the racing industry would most likely want answered by researchers, with the working group planning to first meet on the issue in late May, Benson said. Representatives of the Grayson-Jockey Club Research Foundation and American Association of Equine Practitioners are members of the working group.

“The goal is for all of us to sit in a room and come up with the research we need done,” Benson said. “That way researchers can submit specific projects for us and we can fund them accordingly.”