A racehorse must have “heart,” both figuratively and literally. Without a good heart, even the most well-conformed, ideal-looking young racing prospect might not be a winner. The size of a young horse’s heart has proven to be a reliable predictor of future performance, especially in horses that run longer distances. Quarter Horses need strong hearts, but size is just one important factor since they typically don’t run very long distances.
Jeff Seder and Patti Miller, president and vice-president of EQB, an equine consulting firm based in West Grove near Lancaster, Pennsylvania, advise clients and help them manage their racehorses. Seder and Miller have spent many years perfecting their methods for taking accurate cardiovascular measurements of racehorses’ hearts using echocardiography.
“We image the heart, take various measurements, and then compare that heart to others in a large database,” Miller explains. She has now taken measurements of more than 50,000 racehorses, comparing horses of same age, sex, size and similar degree of training. From these measurements, she can compare horses and try to predict what their abilities will be.
“The mathematics and statistics are very complicated and it requires a huge database,” Seder says. “You can’t compare a 900-pound 14-month old filly to an 1100-pound 16-month old colt. They’re not the same. These young horses are different. You can’t just do ‘yearlings’ and accurately compare them. You must know their age in days, sex and size. They have to be the same in all these aspects to compare them accurately.
“To get several good graded stakes racehorses in the database to compare to when they were young, you must have hundreds of horses to compare to in each weight/age in days/sex and height category. This means you need thousands of horses in your database or you won’t have accurate comparisons. This is one of the reasons it took so long to develop our program,” he says.
“Another reason it took so long is because of the way people were scanning hearts when we started. The veterinary protocol at that time could not give the same results each time when you were in a stall with a yearling at a sale. It might have worked in a university setting with a million-dollar machine where they’ve got the horse under complete control, but out in the field it just didn’t work.
“We actually had to go to the other side of the horse, opposite the heart, and develop a different protocol. We also changed the transducer and the power/megahertz in the signal in the ultrasound to get a different resolution. So, we changed the way it was done, changed the equipment it was done with, and then we built a database,” he explains.
It is also crucial to have technicians who have done this thousands of times, like you would find in a good hospital. “We’ve had the same person, Patti Miller, doing these horses, which is now more than 50,000,” he says. “We started in the early 1980’s, so we’ve been doing it more than 30 years. We needed to do enough horses to show that the data would be reproducible, and we did studies to show that we got the same results every time we did the same horse. The results of these studies are in our published papers.
“It all started with human athletes. In 1976, the East Germans walked away with many Olympic medals. Before that, the Olympics had been a contest primarily between the Soviet Union and the United States. Then suddenly Germany was beating both of us. Everyone was shocked and there were rumors that they had mad scientists recruiting kids from kindergarten in secret sports programs. The U.S. started a movement to do sports-medicine for our Olympic athletes. I was a young lawyer with experience in athletics, and I was called in by some of the Olympic coaches to try to help them,” says Seder.
“I wanted to do horses, not humans, but I became part of the original Olympics sports-medicine movement,” he says. “For a couple years, the company I created was doing half the biomechanics research and services for the U.S. Olympics committee. Then I had to decide whether I wanted to do this full time. I decided to leave in order to develop this technology for racehorses.
“I wanted to take the technologies being developed for human athletes and see if we could make them useful for helping select and manage racehorses,” says Seder. “One of the first things we learned in the Olympic sports-medicine movement was that elite athletes were as different physically as sick/injured people are from normal (healthy) people. All the databases in existence were about normal people or sick/injured people.”
There were no databases for elite athletes. This was uncharted territory.
“They had to build databases for human athletes and I had to do that for horses,” he says. “Everything in the textbooks was about normal, diseased or injured horses, and it didn’t apply. It wasn’t going to work because these athletes are physically different. So, I had to start from scratch.”
Seder took what the Olympic sports-medicine studies found to be different in human athletes and looked at these things in horses. “I looked at about 50 things, but the one that turned out easiest to measure was the size and function of the heart,” he says. “So, I went after that aspect and then couldn’t do it because we didn’t have the right protocol nor the right equipment. We also needed mountains of data. By the time we arrived at something useful, it was 20 years later and I’d spent millions of dollars on research.”
Miller says one of the important things is consistency of the samples. “We do a lot of work at yearling sales, trying to pick out the individuals that look like they can run. A big heart in a horse that can’t run is just a big heart and that horse will never be a winner,” she explains.
EQB uses scientific technology, but has not ignored common sense. “We have declined working with breeding farms that don’t already have a good method of trying to select their athletes. Also, for the research and comparisons, we only use data from horses that went on to have enough starts. In other words, we look mainly at horses we think have potential and who stayed sound enough to have a 3-year-old career,” Miller says.
Some horses have not had enough starts or are unsound. Miller points out that if a horse isn’t sound enough to race or doesn’t have the conformation to run well, it won’t be in this group. It’s not just about big hearts.
“These things can affect the database,” says Miller. “What Jeff has done, and the thing that makes him so special in this business, is that he has amassed a database that just includes previously selected athletes that can run, can go on and are able to train. This is a much stronger approach, involving a more comprehensive genetic package for selection.
“It doesn’t matter how many hearts you have in your database,” she explains. “If these are not the hearts of horses that were pre-selected as athletes, you’ll get the wrong formulas, versus subsequent success.”
Seder says they don’t even look at the heart of a horse until it has passed three or four of their other tests. This is how they separate the good horses from the potentially great horses. “We are trying to distinguish between allowance horses and graded stakes horses. Our database is immense and it’s unique in the fact that these are already all preselected horses. It is a massive database of rare specimens. Then we know what is different about the good ones. It’s the heart in the ones that succeeded. They all had good conformation, good throats, good pedigrees, etc. The difference between them is in the heart,” he says.
Seder says it’s also all about having the right heart for the size, age and sex of the horse. “It has to be a big, strong heart, and we measure the size and quality of the muscle. We talk about big hearts, but it’s much more than that. There are about 10 variables that we evaluate,” he explains.
“We published our findings and have shown that it works, statistically. Our published paper, Journal of Equine Veterinary Science, was the result of looking at 10,000 horses. We watched them in every race they ran during their 3-year-old year, then compiled all the statistics to compare only horses of the same age, sex and size, etc. Our data showed that even if you eliminated all the other differences between these horses and then looked at who succeeded and who didn’t, the heart was the variable that made the difference.
“It’s no longer just a theory, but a proven technology,” he says.
Heart measurements can be one of many clues to racing ability. “For instance, American Pharoah has a phenomenal heart,” says Seder. “He was at the yearling sale at Saratoga when we looked at his heart. He was a beautiful colt and everyone liked him, but he had a cut on his ankle. Ahmed Zayat was thinking about selling him, but with the swelling Zayat ended up bringing the colt back home. Part of our evaluation was to look at the hearts of these yearlings, so we did look at that colt and thought, ‘Oh, my,’ and we advised him to keep that horse.” American Pharoah went on to win the 2015 Triple Crown.
Examining Yearlings At Sales
Heart scanning is becoming more routine at yearling sales. Miller compares it to having a human ultrasound. “If you need ultrasounds, they tell you to have the same technician do it each time and, if possible, the same machine. That’s the best way to have consistency. I am still dragging around this old machine, but it gives a very clear image,” she says.
Because it does the job so well, they searched for and bought every old machine like it that they could find so they wouldn’t have to change to a different kind of machine, and now have about five of them. “All ultrasound machines have distortions as you go deeper. Thus, it is very hard to compare heart sizes from two different kinds of machines. Ultrasound techs will tell you they become very comfortable with the machine they have, and they don’t want to keep changing,” says Miller.
“To be really good at cardiovascular measuring, a person also has to do a lot of homework and know a lot about anatomy,” she says. “Horse’s hearts are all different and they aren’t always exactly in there at the proper angle. Veterinarians understand anatomy, but an ultrasound technician doesn’t unless they have spent a lot of time understanding what they are looking at. It helps to have done a lot of horses. The first few years I measured hearts, 20 years ago, I wasn’t as good at it.”
You also want to have someone who is an expert at handling horses. “Patti was one of the first women jockeys and she’s been a racehorse trainer,” says Seder. “She and her handler for the horses we ultrasound have worked with racehorses their whole lives and that’s all they do. When they go into a stall to do a young horse for a sale, they are professional and know how to keep that horse calm. You can’t just hire someone and send two people and an electrical machine in there with a yearling or you risk having a disaster. In all our scans, we’ve never had a safety issue.
“You can walk into a stall and the resting heart rate can jump from 30 to 120 beats per minute if that horse gets upset,” explains Seder. “You may not be able to detect any outward sign, yet the heart rate jumps to four times the normal rate. So, you must have people who know how to not let that happen or else your data is no good.”
“You are walking into a stall with someone’s long-term investment,” says Miller. “You have to treat it like it is a fine instrument and be very careful with it. We take this very seriously.”
To make sure the horses are calm, they often do these measurements at night when there are fewer people around and less distraction for the horses. “We’ll still do some during the day, but the problem is that we must go a lot slower,” Miller says.
“Anything that lowers blood pressure can change the accuracy of the exam because we are looking at the left ventricle at peak diastole,” she says. “Some people might tranquilize the horse so we can work on it, but that destroys the data. Anything that influences peripheral dilation or if the horse had a bad experience a few minutes before we come into the stall, it won’t be accurate.”
Looking At Quarter Horses
Not many people are scanning hearts of Quarter Horses for comparing potential racing ability, but hearts of running Quarter Horses have been examined in other ways.
“Precocious speed horses like running Quarter Horses generally have smaller, but very powerful, hearts,” states Bill Casner, Texas breeder of Thoroughbreds and Quarter Horses. “The size must be put into context with several other criteria. If the heart is too big, however, it can act like a big billow and not be able to contract with every stride, which becomes the limiting factor for distance.
“Every horse has his maximum cruising speed that he can sustain while being able to breathe with every stride. If a horse goes too fast, he will shorten his stride in the last part of the race.
“It has been said that horses can run 3/8 mile anaerobically, so I would suspect that Quarter Horses can easily run a 1/4 of a mile without going into oxygen debt,” Casner says. “Many Quarter Horses can run all-out from gate to wire, but some can maintain and gain speed late in the race. The reason for this may be having an optimum heart in combination with optimum biomechanics. The ultimate calculation would be measuring stroke volume of the heart, but that has yet to be done effectively in horses.”