Synthetics and Sealed Dirt: The Science, Data and Expert Opinion

Amid the talk of whip use and medication restrictions during the last scheduled California Horse Racing Board (CHRB) meeting, there was another topic that resonated loudly: the safety of Santa Anita's track surface. “We're definitely considering plans in the future, on these rainy days, of almost being like in the Northeast, when they have snow days and take the day off,” said The Stronach Group's COO Tim Ritvo, about the possibility of restricting racing and training on a sealed track.

There's much to dig into when it comes to training and racing on a dirt surface during periods of inclement weather-issues that will be returned to later in the article. But in terms of the health and well-being of the horse, what CHRB vice chair Madeline Auerbach said after the meeting is the “core of what we do,” it also refocuses the issue back on synthetic surfaces, with which California has a torrid and costly relationship. A cold hard look at available race-day fatality data, however, tells a stark story.

According to the Jockey Club's Equine Injury Database (EID), between 2009 and 2018, on average 1.2 horses per 1000 starts were catastrophically injured on synthetics. That number is 1.47 on the grass, and 1.97 on dirt.

Using both CHRB and DRF chart data, the TDN zeroed in on four California tracks: Del Mar, Santa Anita, Hollywood Park and Golden Gate Fields. Between the 2007-2008 season and the 2017-2018 season, on average 1.9 horses per 1000 starts were catastrophically injured on the synthetic tracks in place at those four facilities. That figure was 2.6 for the dirt.

At the end of the day, “the numbers are staggering,” said the University of Kentucky's Mick Peterson, about the marked difference in race-day fatality numbers between the dirt and synthetics. But, as with most issues concerning catastrophic breakdowns, the numbers only tell part of the story.

“I know that there are hundreds fewer horses that are breaking down in front of the crowds, because we have synthetics,” said Peterson. “But what I don't know is how many horses have had shorter careers,” he added, highlighting a common critique of synthetics: that while catastrophic injuries appear to be less on these surfaces, they cause more potentially career-threatening injuries than dirt.

In the award-winning TDN article, “Is This the Death of Synthetic Racing?” which chronicles the failure of synthetic surfaces to garner a foot-hold in North America, trainer Mike Mitchell said that, “I've had more injuries on these tracks than I had on dirt,” with hind-end issues being most prevalent.

In the same article, however, other prominent experts argued the opposite. Renowned veterinarian Dr. Wayne McIlwraith said that bone injuries and joint injuries were significantly lower, “but the absolute number [of soft-tissue injuries] was no higher.”

The problem is, no definitive objective study has been conducted to offer an answer one way or the other. The Thoroughbred Owners and Breeders Association released a 2010 study that found horses running on synthetics were half as likely to suffer career ending injuries as those on the dirt. The scope of the study was fairly limited, however. This 2015 study, using data collected from horses primarily racing and training on synthetics in California, found that the occurrence of non-fatal injuries was lower than other studies using trainer-reported injury data. But again, there was limited participation.

California was at the vanguard of the synthetic revolution of the mid-2000s, when in 2005, the CHRB mandated synthetic surfaces be installed at the state's four main tracks. Nevertheless, these surfaces were bedeviled with maintenance problems. Santa Anita's wax-based cushion track, installed in 2007, was beset with drainage issues after an improper sand was used, and was subsequently replaced with a pro-ride surface. Drainage issues persisted, however, and the pro-ride was ripped out in 2010 and replaced with dirt.

Despite these problems, in terms of catastrophic race-day fatalities, synthetic surfaces at these four tracks still proved safer than dirt. According to this study using data taken from the start of 2004 until the end of 2009, catastrophic breakdowns decreased by 37 percent after the dirt surfaces were converted to synthetics. In a nod to the concerns of trainers who saw an increase in hind end issues on synthetics, the study also found a “relative increase in hind end fatal injuries.

“Unfortunately, they weren't good enough,” admitted trainer Michael Dickinson, inventor of the Tapeta synthetic surface, about the first iteration of synthetics tracks. That said, synthetic surfaces have “come a long way” since then, Dickinson added, including the latest generation of his own, called Tapeta 10.

Dickinson singled out Newcastle–a racetrack in the north of England which replaced its turf course in 2016 with Tapeta–as a poster-child for Tapeta 10. While many were initially skeptical of the change, said Dickinson, Newcastle is now a popular destination for top trainers, including many based hours away in Newmarket.

“John Gosden ships his best maidens seven hours in a van just to run on that surface,” said Dickinson, pin-pointing a number of Gosden-trained stars-like duel Arc-winning Enable, GI Royal Ascot winning Without Parole, and GI Ascot Gold Cup winning Stradivarius-who all made early career starts there. “I mean, they love Newcastle.”

Of course, the climate in Newcastle-on the same latitude as the city of Omsk, in Siberian Russia-is vastly different to the toasty climes of SoCal. But according to Dickinson, the latest version of Tapeta is “much less temperature sensitive” than its earlier cousin. “It's alright on the heat,” he said.

Irwin Driedger, director of Thoroughbred Racing Surfaces at Woodbine, agrees. “We go from one extreme to another, from really hot 90-degree weather to zero temperatures,” said Driedger, who manages Woodbine's Tapeta surface, installed in 2016. “When it's hot, we put some water on to maintain the temperature, and when it's really cold, we loosen it up and don't pack it up as tight,” said Driedger.

In fact, the cold weather, Driedger said, is tougher on the surface than the heat. “It won't break down as quickly in the heat, but it will soften up,” he said. “Last year, when a whole lot of tracks were cancelling because of heat in the east, we never cancelled or missed a day of racing. And you never saw a change in the track on race-day.”

With Santa Anita's checkered history with heavy rain in mind, both with synthetics and dirt, Driedger said that the track has “no” issues with drainage. “We just had on Saturday an inch of rain and about a quarter inch of snow, and the next day it froze, and we didn't miss a beat,” he said.

Most importantly, Woodbine's race-day fatality record on the Tapeta holds up well against numbers for dirt. Last year, 1.3 horses were fatally injured per 1000 starts at Woodbine. That number was 0.63 in 2017, and 1.07 in 2016.

Of course, key issues like racetrack surfaces invariably catalyze the old butterfly effect throughout the industry. Take this excellent piece in the TDN last week, in which Sid Fernando emphasizes the commercial specter of decades of dirt-breeding in the U.S. Historically speaking, synthetics haven't been terribly popular with horseplayers either. Then there's the cost of installing them and renewing the materials. According to Driedger, Woodbine's new Tapeta surface cost “up and around” $10 million to install. But on a strictly welfare basis, synthetics clearly cause less horses to catastrophically break-down than the dirt. A persuasive argument for reform, right?

Not so fast, said Peterson, who said that he believes dirt could be as safe as synthetic surfaces, if the science was there to maintain them properly. “But we're not headed that way,” Peterson added. “We've made no real progress in the seven years I've been saying that.”

A big part of the problem is the industry's wholesale lack of funding into researching better protocols for maintaining moisture content to improve its consistency, said Peterson. “The total investment in trying to do better moisture control on dirt tracks has been almost nothing compared to what has been spent on synthetic tracks that have then been removed,” he said.

To understand why consistency is important, it's important to know the three main phases of a horse's stride, and the immense forces, both horizontal and vertical, at play when a horse is at racing pace, said Peterson. Phase one: the initial impact to the hoof and leg. Two: the hoof slides to a stop, and the foreleg is momentarily vertical. Three: the roll-over phase as the horse propels itself forward.

On any surface, the horse's hoof slides a certain distance before it stops. The trick is to find the right amount of slide. Too little, and the horizontal loading on the leg is too great. Too much slide can lead to “misalignment” of the loading on the ankle and knee joints. What better surface moisture consistency could do is narrow the gap between synthetics and dirt as to the variation in sliding, said Peterson.

“The average slide on dirt was greater than it was on synthetic,” said Peterson about a study he worked on, but never published. “But in the most extreme cases, you had less slide on dirt than you did on synthetics. The key to dirt is the variation was so much greater than it was on synthetic. The variation was so small on synthetic, even between different manufacturers, different temperatures.”

Which brings us neatly back to the issue of training and racing on a hard or sealed surface. “If sealing the track was a problem, then the catastrophic injury rate at Belmont, Laurel Park, and at Aqueduct would be awful,” said Peterson, highlighting racetracks that frequently endure periods of inclement weather, and as such are routinely sealed. “But they're not, right?”

Indeed, using EID data, the average catastrophic injury rates per 1000 starts over the past five year at Belmont Park (1.35) and at Aqueduct (1.55) are both lower than the average fatality rate nationally on the dirt during the same period: 1.82. Laurel Park's is marginally higher, at 2.01.

The key issue once again, said Peterson, is consistency, and the different set of conditions encountered on wet and dry tracks, as well as surfaces that don't dry uniformly-issues that can affect the amount of “slide” underfoot. The track maintenance crews and the trainers in New York are more accustomed to inclement weather than their California-based cohorts, and adapt their maintenance protocols and training programs accordingly, said Peterson.

At the same time, “to be fair to the California trainers, if you gave the trainers at Aqueduct and Laurel a dry spell, they might have as hard a time as the California trainers do in a rainy period,” said Peterson. “The water trucks and drivers at Santa Anita are some of the best in the country.”

The context here is that it's not just the track management who have to adapt to their conditions-it's the trainers, too, who need to be mindful of subjecting their horses to unfamiliar conditions. Indeed, experts in bone physiology stress the importance of giving a horse time to acclimatize to unusual training surfaces.

While racehorses can certainly adapt to sustained training on hard or sealed tracks, such surfaces transmit “greater loads” to the limbs during each stride, leading to increased “microscopic damage” within the skeleton, said Sue Stover, a professor of anatomy, physiology and cell biology at UC Davis, about the tiny fractures sustained by racehorses on a daily basis. “That must be repaired by the body to maintain skeletal health and resist injury.”

In the same vein, inconsistent surfaces can also cause “unusual loads” on the skeleton, said Stover. “Loads that the skeleton has not adapted to during training and thus could increase the risk for injury,” she added. As such, training activities “should be modified” when horses encounter hard or inconsistent surfaces, said Stover.

“In general, the length, which is directly related to the number of strides, of high-speed activities should be reduced to keep the amount of microscopic damage to a level that allows the skeleton to recover from the damage and strengthen,” said Stover. “If training and racing are too intense, the skeleton can not only not strengthen, but can become weaker and at increased risk for injury.”

When asked if he thought the trainers had, as a whole, adequately modified their training programs during this unusually wet winter in California, CHRB equine medical director Rick Arthur pointed to the work tabs through that period. “You can draw your own conclusions,” he said.

“What I will tell you is that I used to work for a guy called Willard Proctor. Old time trainer,” said Arthur. “We had a situation where the track was sealed for weeks. They opened it up, and a lot of trainers just had to work their horses. The next morning, these trainers were complaining about all the sore horses they had. Willard Proctor hadn't worked any of his horses, and he told the trainer next to him, 'well, you know what, when the track's bad, you don't work your horses.'”

As California Thoroughbred Trainers president Jim Cassidy explained, when it rains on and off for a period of time, “a lot of guys feel pressured, if they haven't done anything for days and days, to do something. So, they've got to bite their lip and go on with it.”

But Cassidy said that he also believes more could have been done to the track to make it safer. “They don't have to seal it, they can float it,” said Cassidy, about a maintenance procedure that still protects the track from rain, but doesn't necessarily leave it as hard as when its sealed.

At the end of the day, Cassidy said that he's unsure about how to apportion blame. “I'd have a better assessment by the end of the meet, if we don't have any more rain,” he said. Nevertheless, as a result of the changes made to the dirt surface since former Santa Anita track superintendent Dennis Moore was brought back on board, “if we go the rest of the year with no issues,” Cassidy would be more inclined to fault the track, he said.

Others see the situation much more black-and-white. “We've had 100 years to perfect dirt, and we haven't and we never will,” said Dickinson. “Now we've only had a few years to perfect synthetics, and we've still got room to improve.”