This week's Animal Welfare Forum, held at the Association of Racing Commissioners International (ARCI) 84th annual conference in Hot Springs, Arkansas included discussion of how racing regulators might address abuse of equine medications known as bisphosphonates.
Note: ARCI members, representing individual racing jurisdictions around the country, are the only independent entities recognized by law to license, make and enforce rules and adjudicate matters pertaining to racing.
Background
Bisphosphonates are a class of drug prescribed to horses (and humans) to prevent bone density loss. The drugs--including those sold under brand names like Tildren® and Osphos®--gained widespread use originally because of their potential benefits to horses for treatment of navicular disease. They received FDA approval for that use in 2014, in horses over four years old. In recent years, bisphosphonates are reportedly in use in yearling and two-year-old Thoroughbreds, sport horses and show horses.
Hoof Blog note: The most recent research on bisphosphonates indexed by HoofSearch was published two weeks ago, on March 20, 2018. "Tiludronate and clodronate do not affect bone structure or remodeling kinetics over a 60 day randomized trial" by HA Richbourg at al was based on pre- and post-medication microCT and histology of bone biopsies from 19 clinically normal young Thoroughbreds. The research was conducted at Louisiana State University and published in BMC Veterinary Research as an Open Access (free to read or download) article.
Hoof Blog note: The most recent research on bisphosphonates indexed by HoofSearch was published two weeks ago, on March 20, 2018. "Tiludronate and clodronate do not affect bone structure or remodeling kinetics over a 60 day randomized trial" by HA Richbourg at al was based on pre- and post-medication microCT and histology of bone biopsies from 19 clinically normal young Thoroughbreds. The research was conducted at Louisiana State University and published in BMC Veterinary Research as an Open Access (free to read or download) article.
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According to the ARCI, bisphosphonates might have some therapeutic value for older racehorses but speakers at the ARCI's Conference on Equine Welfare and Racing Integrity warned of the potential harm caused by such treatments for young horses such as yearlings and two-year-olds. The remainder of this article was edited from a press release provided by the ARCI.
Dr. Jeff Blea, a Southern California veterinarian who is the past president of the American Association of Equine Practitioners and heads its racing committee, called bisphosphonates “a nuclear button right now, not only in the racing industry but in the breeding industry.”
Additionally, Dr. Lynn Hovda, the Minnesota Racing Commission’s equine medical director, noted that bisphosphonates don’t just impact what could be a sore bone or joint; they go throughout the skeletal system.
Dr. Sue Stover, a professor at the University of California Davis School of Veterinary Medicine, said the rational for giving young horses bisphosphonates is to ward off stress fractures, joint problems and some abnormalities. “Ultimately it was just the silver bullet of preventing all these problems,” she said.
However, Stover said that bisphosphonates in young horses actually interfere with the development and growth of bone, reduce bone’s ability to heal and make bone more susceptible to cracks. One study of Israel military recruits showed that bisphosphonates did not prevent stress fractures when given before training, she said.
One of her major concerns is that bisphosphonates, as analgesics, have the potential to mask pain.
Conference attendee Carrie Brogden, a breeder and consigner whose Machmer Hall Farm in Paris, Kentucky, bred the champion Thoroughbred mare Tepin, commented that she and her husband Craig do not treat horses with bisphosphonates but that the panel opened her eyes about what could be an industry problem.
“You’re talking about horses who may have been treated as yearlings coming down the race pipeline,” she said. “I guess it’s a small sample right now. But this is being kind of pushed in Lexington as the safe cure, not as something to be avoided.”
Blea suggested that taking a page from the British Horseracing Authority’s ban on bisphosphonates in racehorses under 3 1/2 years old, and requiring a 30-day “stand down” from racing, “would be a good place to start” for regulating the drugs. He said the AAEP recently assembled a committee to discuss bisphosphonates and mentioned a talk on the subject that he gave two years ago to several hundred veterinarians.
Blea said that he had asked how many of the attendees were using bisphosphonates in their practices. “There might have been five or six people raise their hands. After the talk, 25 people came up to me asked me, ‘Is there a test for it?’
“The reality is that we don’t know enough about it," he continued. "I’ve spoken to practitioners who have told me it is rampant in the Thoroughbred yearling industry, rampant in the two-year-old training sales. I know it’s being used on the racetrack, though I don’t believe it’s being used as much on the racetrack as people think. I think it’s one of those things that have come and gone.”
But John Campbell, the legendary harness-racing driver who last year retired to become president and CEO of the Hambletonian Society, said the Standardbred industry has had “great luck” using bisphosphonates to treat young horses with distal cannon-bone disease with “no adverse affects that I can see.” He noted that Thoroughbreds are much more at risk for catastrophic injuries than the gaited Standardbreds.
Jurisdiction over horse medication
ARCI president Ed Martin urged racing regulators to start working on a model rule as to when jurisdiction over a horse begins, which could allow them to address the concern over bisphosphonates. One of ARCI’s missions is to create model rules that provide the member regulatory groups a blueprint for their own laws or legislation dealing with all aspects of horse racing.
“I think it would behoove all of us to work on a model regulatory policy so we have uniformity in terms of when the horse should come under the jurisdiction of the racing commission,” Martin said. “When we talk about out-of-competition testing or questioning the use of certain medications, the first thing somebody is going to say is, ‘You don’t have jurisdiction over this horse, and you don’t regulate the practice of veterinary medicine.’”
Matt Iuliano, The Jockey Club’s executive vice president, said that about 75 percent of Thoroughbreds will make a start by age 4, leaving a 25-percent “leakage rate.” He suggested a more cost-effective and logical place to put horses under regulatory control is once they have a timed workout, indicating an intent to race. “You’ve probably taken that 75 percent to 90 percent,” he said.
Eric Hamelback, CEO of the National Horsemen’s Benevolent & Protective Association, agreed with starting regularity control with a horse’s first published work. He expressed hope for a common-sense rule that would be fair to everyone, while cautioning of bisphosphonates, “There is a lack of facts and research being done. We don’t want to go after writing rules just to write rules. Finding out exactly, if there is a concern — and what that concern is — to me is the most important first stage. And then where we’re going to attack and fix the problem.”
Identifying risk — and protective — factors in horses
Dr. Scott Palmer, the equine medical director for the New York Gaming Association, discussed identifying risk factors in racing, including those at “boutique” meets such as Saratoga, Del Mar and Keeneland, with the inherent demands to get owners’ horses to those races because of their exceptional purse money and prestige.
Palmer cited some risk factors as being on the “vets” list for an infirmity, not racing at two, trainer change, switching to a different track surface and dropping in class. He said protective factors also must be identified.
Palmer said changes that have established themselves as diminishing risks would not all be popular and could require a change in mindset, such as writing fewer cheap claiming races, limiting the claiming purse to twice the value of the horse, consolidating race meets, biosecurity and limiting the number of stalls given the large outfits. He said racetrack safety accreditation by the National Thoroughbred Racing Association is important. Also mentioned: continuing education for veterinarians, trainers and assistant trainers, along with increased scrutiny of horses seeking removal from the vets list after a long layoff.
“We’re not going to get rid of fixed risk factors, but we can mitigate them,” Palmer said.
Dr. Rick Arthur advises the California Horse Racing Board (CHRB) on equine medication and drug testing, veterinary medicine and the health and safety of horses under CHRB’s jurisdiction. After a rash of fatalities in 2016, Del Mar’s actions included allowing only horses having timed workouts to be on the track for the first 10 minutes following a renovation break and giving up a week of racing to allow additional time to get the track in shape for the meet after the property was used for the San Diego County Fair.
Arthur cited a study that determined horses scratched by a regulatory veterinarian did not race back for 110 days on average, while the average horse ran back in about 40 days.
“The bottom line is (that) we’re actually identifying the right horse,” he said of vet scratches. “The real issue is: are we identifying all the horses we should?”
The 2018 ARCI Conference continues through Friday.
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