Veterinary experts work to stay ahead of equine doping

Elite athletes train for years to reach the top of their game. Yet some succumb to temptation, using performance-enhancing drugs to gain a slight edge over their competitors.

The same is true in equine sports. Though the vast majority of competitors come by their success honestly, some horses have been found with all manner of performance-enhancing drugs in their systems, used by unscrupulous trainers or veterinarians to give the animals an unfair advantage over the competition in races and sporting events. By masking the signs of overexertion or injury, such illicit drugs may set up a horse—and its rider—for harm, in addition to compromising the integrity of the sport.

At Penn’s School of Veterinary Medicine, researchers and veterinarians work to maintain the welfare of horses involved in sports like racing, jumping, and eventing, while also helping ensure that participants in those events start on an even playing field. 

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“If horses are treated with something that is covering up an injury or building muscle or bone in an unnatural way, it can predispose them to an injury,” says Mary Robinson, director of Penn Vet’s Equine Pharmacology Research Laboratory (EPRL). “There are always risks; these are high-speed sports. But we want to do everything we can to make sure there is no unneeded risk to the horse or to the jockey.”

Robinson directs the research lab, located on Penn Vet’s New Bolton Center campus in Kennett Square, as well as the Pennsylvania Equine Toxicology and Research Laboratory (PETRL), which is located in West Chester and owned by the Pennsylvania Department of Agriculture. 

The two labs work in tandem: PETRL is where the forensics work occurs, testing 35,000 blood and urine samples each year from horses competing at Pennsylvania’s six race tracks. It is also where analytical chemists from Penn use cutting-edge science to develop new tests to ascertain whether a particular drug is present in a horse’s system. At New Bolton Center’s EPRL, researchers study the pharmacology of drugs to understand how the horse’s body processes them and how they may affect performance outcomes.

Decades of innovation

Penn has been involved in developing new tests for equine doping since 1979, when Lawrence Soma, Robinson’s predecessor, signed a contract with the racing commission to do so. Now Penn is directly connected to the work, with 28 Penn employees conducting research and evaluating samples. 

As in every field of science, the drug tests used have evolved steadily in sophistication. Today, the gold standard is liquid chromatography coupled to mass spectrometry, or LC-MS, which physically separates different components of a sample and then analyzes them based on their particular masses. 

“This process gives us a fingerprint of a substance that allows us to identify the specific peptides we’re looking for,” says Fuyu Guan, research associate professor of equine forensic chemistry. 

The labs also use different forms of mass spectrometers to detect substances. The equipment is highly refined and expensive. A single LC-MS instrument costs roughly $500,000, and other pieces cost roughly half that. The lab has 14 of these systems, funding for which has been provided by the Pennsylvania State Horse Racing Commission, Pennsylvania Harness Horsemen’s Association, and Meadows Standardbred Owners Association, among other sources.

One of the most significant advances the lab has achieved is erythropoietin (EPO) testing. Some might be familiar with EPO from news coverage of Lance Armstrong, but human recombinant EPO, which boosts the blood’s ability to carry oxygen, has also been used in horse racing. It’s challenging to detect, Guan notes, because, like humans, horses have a natural source of EPO, and human recombinant EPO is effective even at very low concentrations. In 2006, Penn Vet was the first lab to develop a test to detect recombinant EPO in horses, a test that is now used around the world.

“That was a really groundbreaking project,” Robinson says, and one that won recognition and awards from numerous associations and attention from the World Anti-Doping Agency.

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The work of anti-doping labs is often described to be in a kind of arms’ race with dishonest athletes. That’s because for every new drug coming into illicit use for performance-enhancing purposes, researchers have had to develop a new way of testing for its presence. Then the dopers begin developing ways of avoiding that detection. 

That has been the case with substances such as cobalt, an essential mineral that, when given in large amounts, boosts red blood cell counts. Working with Penn Vet toxicologist Lisa Murphy, PETRL developed a test to identify a normal range for cobalt, prompting a new regulation to be adopted by the racing industry. Over the years, the lab has also worked to deter the use of anabolic steroids, clenbuterol, and other performance-enhancing substances, with sensitive and specific tests.

More recently, Guan and the PETRL team have developed yet another paradigm-shifting assay that allows them to step ahead of that arms’ race, making life more complicated for would-be banned substance users. 

Published last year in a top journal for analytical chemistry, the new screening method uses liquid chromatography coupled to high-resolution mass spectrometry to extract and detect dozens of peptides—even those that are not yet characterized—from urine or blood samples. The acquired data can then be stored and accessed later if an animal is suspected of having been given a banned substance. 

“The limitation of other methods is that they target only known peptides,” says Robinson. “This gives us a way to detect the unknown.”

As a proof-of-concept for this novel method, Guan found he was able to identify metabolites of dermorphin, a natural opioid extracted from the skin of South American frogs that acts as a powerful painkiller, even though the metabolites were not included on the list of drugs to be analyzed at the time of the initial screening.  

“It’s an amazing technology,” says Guan. “With this method, we can acquire data and later come back and do data mining to find unknown peptides. It’s really a revolutionary way of doing things.”

Full complement

New Bolton’s facilities enable scientists to translate the insights gleaned by chemists like Guan into an understanding of how to keep horses safe. Researchers make use of a specialized research barn, horse exerciser, and treadmill and perform precise pharmacokinetic and pharmacodynamic studies to obtain information about how long after taking certain drugs an animal can safely and ethically return to competition.

“Even if a drug is given therapeutically, we need to know how long to wait after giving that drug until the horse can return to racing,” Robinson says.

The lab’s methods are becoming increasing refined. With funding from the racing commission, Penn Vet has created an “exercised” herd of horses that will be kept in top condition to more accurately reflect how fit horses respond to drugs. 

Researchers are also embarking on studies that accurately measure a horse’s VO2 max—a reflection of cardiovascular fitness—and developing ways to evaluate the performance-enhancing effects of things other than drugs, such as shockwave therapy. 

Joanne Haughan, a research associate in the lab who coordinates the EPRL studies, says that, even though equine sports across the board are relatively “clean,” keeping up with testing helps keep them that way.

“Racehorses in Pennsylvania are all tested both in and out of competition,” says Haughan. “If you think about it, testing plays a huge role in prevention of the problem, as a deterrent to using banned substances.”

For that reason, PETRL doesn’t share the full list of the drugs they’re currently working on. But Robinson and others in the lab are constantly performing outreach, talking with trainers and with veterinarians around the state, the nation and the globe to stay ahead of would-be dopers.

“For me, animal welfare is the most important piece,” Robinson says. “We want to keep these animals and the jockeys and drivers safe.”