Mill Spring, N.C. - Dr. Ken Marcella is a member of the USEF Endurance Veterinary Advisory Group, a Fédération Équestre Internationale 4*-rated official endurance veterinarian, and owner of KLM Equine in Canton, Ga.
What is a control exam and why is it important?
Endurance is unique in that, during an event, there are numerous times horses will be examined and checked to ensure that they are sound, metabolically stable, and tolerating the demands of the competition on that day. The “control exam” or “vet gate exam” are terms applied to these checks. These exams are extremely important and a crucial part of why the sport of endurance can be run with a high degree of assurance that the participating horses will be safe and that their welfare is constantly being protected. The physiological demands of the sport ask a lot physically of endurance horses; these equine athletes are often functioning at the maximum limits possible, and it is the duty of the Veterinary Commission, through the examinations done at each control check, to ensure that horses stay on the safe side of those physiological demands.
What is the Veterinary Commission?
The Veterinary Commission is the group of veterinarians that are working at a particular event. The number of vets present will be determined by the number of horses entered, to ensure that there are enough veterinarians to rapidly and efficiently do the exams. One seasoned veterinarian with extensive experience will be the designated president of the Veterinary Commission. Vets are star-rated, just like events. The training, apprentice time, continuing education, and exposure through time working events make up increasingly higher star ratings that would allow one to work a World Equestrian Games (WEG) or Olympic Games. Another veterinarian from a set distance away from the event will function as the foreign veterinary delegate. The other members of the commission are referred to as “line vets,” and they will be the ones actually checking each horse at control checks. The Veterinary Commission, according to Fédération Equestre Internationale rules, “has absolute control on all matters concerning horse safety, health and welfare.” Any issues, problems, or concerns that arise during an endurance event will be dealt with by members of the Veterinary Commission, the Ground Jury and the Organizing Committee.
What does the Veterinary Commission evaluate at a check?
First, remember that all the horses in an event have previously been examined by the Veterinary Commission. The day or evening before, these horses have been evaluated and had all their physiologic parameters checked and recorded on the official vet card, which will stay with the horse through the ride and will be available to the vet at each control exam. In this way, a dynamic record of the horse is being created. That shows the vets how the horse was previously and how it has been doing through the event, and it allows for some reasonable decisions to be made about the horse’s ability to continue.
When a horse comes in off the trail, it will be cooled with water and walked to get its heart rate down. During exercise, horses will have an elevated heart rate that will come back down soon after they stop doing muscular work. The Veterinary Commission and the Ground Jury will set a particular heart rate (usually 64 beats per minute) that horses must be down to before they can pass their control exam and begin their hold time. So the first thing that is checked in a control exam is the heart rate. If the heart rate is acceptable, then the rest of the exam continues. The vet will check the heart rate and then ask that the horse be trotted down a straight, flat lane for 125 feet, turned, and trotted back. A second heart rate will be checked one minute from the first, and the two compared. This is called a Cardiac Recovery Index, and extensive research has shown that this value is an excellent way to tell if a horse is tolerating the degree of stress associated with the weather, the terrain, and the level of competition.
Next, the line vet will check the horse’s mucous membrane color and its moisture. A capillary-refill test will be done (a finger is pressed to the gums to blanch out the small blood vessels there, and the time it takes for color to be restored after the finger is removed is recorded). Additional tests of a horse’s state of hydration are done, including the time it takes for the jugular vein to fill, and the skin response to pinching will also be evaluated and recorded. Additionally, the abdominal or gut sounds will be evaluated; hydrated horses doing well will have good gut sounds in all areas of the abdomen.
The back, withers, and girth areas are all palpated, and the responses are recorded. Large muscle groups of the back, rump, and upper legs will all be palpated. All areas of the lower legs are examined, along with the feet. The vet will be looking for trauma, swelling, or anything else that is out of the ordinary. This examination usually takes five minutes or so. The vet will record all these findings on the horse’s vet card, and, if all is well, then the horse will be released from the control exam area and can now go back to its crew area to eat, rest, and wait for its hold time to be over. These hold times vary between events and even between stages of an event. They have been determined by the vets and Ground Jury based on the demands of weather, trail, or other factors. The hold times and heart rate levels are all designed to help ensure that the horses do not go too fast and that they have adequate time to rest and recover before going back out on the trail. These are considered welfare decisions and are taken very seriously.
How many such control exams are there at an FEI endurance competition like the WEG?
The WEG and other such three-star and four-star events are contested over 100 miles (160 km), so there are generally five control exams, plus a final completion check at the end of the distance.
What requirements are there for a horse entering an endurance ride? Is the sport open to all breeds? Are there age requirements or other requirements for horses?
Endurance is open to all breeds of horses and, at shorter distances, there can be a large variety of breeds at events, including Tennessee Walking Horses competing alongside Paso Finos, Quarter Horses, Morgan horses, and many others. At the upper levels, because of the demands of the sport, there are few breeds other than Arabians represented. The Arabian is well suited to this sport because of its generally smaller weight and size, which creates a more favorable weight-to-surface-area ratio that is important in sweating, cooling, and electrolyte use (think human marathoner versus a football lineman). More heavily muscled breeds tend to fatigue at longer distances because of the added weight they must carry. That increased muscle generates more heat leading to heat stress, dehydration, and reduced performance levels. The Arabian also has lighter but very dense, strong bone and larger feet for its size than other breeds. These genetic traits tolerate the pounding of many endurance miles. A larger lung capacity for its size also make this breed the perfect distance horse.
There are age requirements, as well, and horses competing in one-star and two-star events must be six years of age. Three-star events require that horses be seven years of age, and all WEG horses (four-star) will be at least eight years of age. This allows them to grow and mature and to be able to handle the stress of competition at that level. Additionally, horses must qualify (with certain minimal speeds over set distances) at novice levels, then at each star level as they progress in the sport. Once a qualification is earned, horses are eligible to compete in a level for a 24-month period. If the next level qualification is not earned within this 24-month period, then the horse must compete again in its existing level before progressing further. With this system in place, horses should not be competing at levels that they are not ready for, and it keeps the competition levels consistent: weaker, slower horses are not put at risk trying to keep up with stronger, faster horses.
There are other safeguards in place as well. There are mandatory rest periods for endurance horses following competitions. Longer rest periods are required following longer distances, with adjustments made for concerns raised if a horse is removed from competition for lameness or metabolic reasons. Very few other equine disciplines put such rules in place safeguarding the welfare of competitors.
What other protections are in place for horses competing in endurance rides?
The continual evaluation by the Veterinary Commission at each control check is probably the best protection. If any changes in metabolic or lameness parameters are noted and deemed to be of concern by a line vet, then a vote is taken. In this procedure, the line vet who examined the horse, the president of the Veterinary Commission, and the foreign veterinary delegate all examine the horse independently, watch the horse trot, and complete a full exam. Then there is a silent, blind vote (“pass” or “fail” labelled poker chips are passed by each vet to a steward, who then tallies the vote and communicates the results to the rider), and the horse is either determined to be okay to continue or is stopped and not allowed to go back on the trail. If there are significant issues noted at this exam, then the horse will be sent to the treatment vets for immediate evaluation and assistance. This system has proven to be the best possible method of safeguarding the health and welfare of equine endurance athletes.
Endurance riders pay exceptionally close attention to the details of their horses’ physiology. Can you describe that and detail the level of knowledge these riders have about their equines?
Endurance is one of the most advanced areas of equine sport, in terms of using science to try to improve performance. Endurance riders spend a lot of time with their horses, as these horses routinely train between 15 to 20 miles at a session and will do even longer sets with weekly distance levels often near 100 miles or more. That is a lot of time to spend atop your horse, and there is, not surprisingly, a strong bond of understanding that develops between an endurance rider and his or her horse. I think it is very similar to a musher and a dog sled team, because of the solitary miles spent together and the mutual dependency when far out on the trail, often removed from any other assistance. Most endurance riders train wearing a GPS and heart rate monitor so they know exactly how hard their horse is working, how far they have gone and how fast, and they have a good deal of previously built-up data to be able to compare recovery rates, peak work effort, and any number of parameters. Many endurance riders have completed multiple blood tests, so they know the best electrolyte mix for their individual horse and the best diet and supplement plan. Exercise programs are charted and individualized, and attention is paid to their horse when current performance does not match standards. These riders also have a “feel” and knowledge about their horses from all that time spent together, and they can sense changes and differences, which often show up before more scientific methods alert a problem. This combination of science and horsemanship makes the endurance horse and rider generally a very self-aware team. When you add in the teams’ crew—the other people that are trained and responsible for feeding, cooling, trotting the horse out, and tack care during rest holds—you have a knowledgeable and highly focused group associated with each horse competing in the WEG and such events.
Photo by Taylor Pence/US Equestrian