Page 29 - June 2005 The Game

Your Thoroughbred Racing Community Newspaper The Game, June 2005 29
Behind the Times
MENDING WITH MARROW
Equine Health
By Harlan Abbey
If two horses are entered in the same race, and one shows a three furlong workout in :36 and the other works the same distance in 35.5, does that indicate the second horse is in sharper condition than his rival?
It ain't necessarily so, according to Dave Regan, a clocker at Fort Erie, who then continued on to explain some of the many variables that do not show up in racetrack programs and the Racing Form past performances.
Most racing fans know that the letter "b" next to a workout time means the horse was "breezing" and that the letter "h" means the workout was done "handily." But just exactly do those two terms mean, Regan was asked during a recent interview.
"Breezing," he pointed out to this reporter, "means the horse is basically running on his own, with no urging from the rider. The rider has a good
hold and the horse
is running easily. 'Handily,' on the other hand, means the rider is urging the horse, pushing on its neck or maybe using the stick. It's much closer to racing speed."
"But," he
continued, "there
are even more
variables. For instance, does the rider first sit down on the horse at, for example, the half-mile pole and then start urging him on? Or does he speed up on the horse before he reaches the half-mile pole, so that the horse is going at full speed when I snap my stop watch to start timing the workout? And then there are some trainers who never work their horses very fast."
Timing workouts at all racetracks is a team effort. At Fort Erie, Mary Ann Mullen is stationed at the clocker's stand at the head of the homestretch and Regan along with head clocker William McGirr, are in an office at the top level of the grandstand. Mullen gives McGirr and Regan the names of the horses and how far they are going to work. But with 80 or 90 horses working out on some days early in the season, the clockers will check the foal registration papers they have on file to double-check a horse's head or leg markings if there is a question as to the animal's identity.
"Most early-season workouts are three or four furlongs in distance, Regan said, because the horses are not yet fully fit, adding: "Most workouts are three, four or five furlongs. Later in the year a few horses -- not a lot -- will work six or seven furlongs or even a mile. Depending on the track conditions, normal time for a three-furlong 'breeze' is :36 or :37 seconds. A good 'handily' work for the same distance is :35 'and change.' It's rare to see three furlongs in :34, that's close to racing speed."
Regan said the fastest workout he remembers in all of the 2004 season at Fort Erie was a :46 half-mile breeze by Emerald Earrings, who went on to win a stakes at Woodbine.
Most racing fans also know that a workout time in bold face numerals indicates that the work was the fastest of all other horses working that distance on that same day. That can be significant, Regan noted, pointing out that "Two of the three horses on opening day that showed black type works won their races. That indicated they were in sharp form. But again, some trainers prefer that their horses just breeze and then gallop out strong past the finish line."
Regan is the son of longtime owner and the Ontario Horsemen’s Benevolent and Protective Association’s president Larry Regan. He obviously inherited his love of horses but began his career at the racetrack as a blacksmith after taking the 18-week course at Seneca College and then serving as apprentice for three years to the late Billy Hibbs. "I watched him put shoes on Kentucky Derby winner Sunny's Halo," recalled Regan, "but the best horses I put shoes on by myself were Deputy Minister, Canadian Oaks winner Avowal and Phoenix Factor.
by Karen Briggs
Dave Landry Photo
Fort Erie Clocker & Paddock Blacksmith David Regan
CONTINUED PAGE 37 - SEE DAVE REGAN
When tendons or ligaments are injured, the healing touch might just come from borrowed stem cells.
On the list of career-ending injuries, tears of the suspensory ligament rank right up there near the top.
The problem with ligaments is that, while they do heal, they are almost never as resilient as they were before the injury. Scar tissue that forms during the repair process isn’t as elastic as the original tissue nor as strong, so only about 15% to 20% of high-performance horses who suffer suspensory injuries ever return to full work.
Tears to the superficial and/or deep digital flexor tendons (the classic ‘bowed tendon’) have almost as dismal a track record, for the same reasons. Both tendons and ligaments of the lower limbs heal slowly and incompletely because they’re poorly vascularized. In contrast, the blood-vessel-rich muscles and skin have the benefit of lots of repair materials being swept in their direction - but there’s no muscle to speak of below the knees and hocks, just the delicate apparatus which stretches and flexes the joints of the fetlock, pastern, and foot.
Veterinarians have been searching for a way to encourage better healing of equine tendons and ligaments for decades. Now there appear to be some fantastic new techniques which are making a world of difference in high-performance horses, and they’re based on stem cell therapy.
Douglas Herthel DVM, of the Alamo Pintado Equine Clinic in Los Olivos, California, pioneered the use of bone marrow in tendon and ligament injuries a few years ago, and claims an impressive success rate in excess of 80% (meaning the treated horses returned to their previous level of performance 12 months after injuring themselves). Now his technique is being widely used across North America.
Bone marrow, says Herthel, is a tremendous source of tissue healing components that ligaments and tendons lack. It’s a nursery for blood and for tissue growth, so it’s rich in hormonal growth factors, collagen matrix (a framework for fibroblasts to lay down new tissue), and stem cells.
Ah, yes, stem cells. Mysterious and controversial, but brimming with potential, stem cells are primitive cells which have the ability to transform themselves into a wide variety of tissues, from muscle to cartilage to tendon, in order to help heal injuries. They’re the elastic superheroes of the body, able to come to the rescue in whatever form they’re most needed, given the correct stimulation. What makes them controversial is that researchers originally thought they could be harvested only from embryos. But the potential of stem cell thera- py has exploded now that we know they can be harvest- ed from a number of different tissues in adult horses (or humans, for that matter). In the case of Herthel’s bone marrow method of ligament repair, the marrow (and the stem cells and other factors it contains) is gathered from the injured horse’s own sternum (the breastbone, easily accessible when the horse is under general anaesthesia).
Here’s how it works: ultrasound is used to guide a number of needles into the anaesthetized horse’s ligament or tendon lesion. The needles are pre-placed, and then bone marrow is aspirated from the middle cavity of the sternum. Because the marrow degrades quickly, it’s immediately injected into the lesion sites. Recovery usually consists of a couple of weeks of stall rest with hand-walking, followed by light exercise on a treadmill, hotwalker, or Aquatread apparatus, with the gentle movement stimulating good collagen quality and fibre alignment. Meanwhile the bone marrow is contributing to increased vascularity (blood supply), encouraging more oxygen to get to the injured tissue, and improving the quota of fibroblasts (ligament-building
cells), as well as providing a matrix on which they can build strong, elastic fibres.
100 horses were treated with a single dose of bone marrow from their own bodies in a pilot study conducted between 1995 and 1998. Of those 100 animals, 84% returned to full soundness and only 5% did not improve. Herthel cites one eight-year-old Thoroughbred with matching front high suspensory tears, who returned to racing a year after bone marrow treatment and ran the fastest time of his career.
These results are seriously encouraging, but bone marrow injection is not the only way of applying stem cell therapy to injured tendons and ligaments. In fact, some researchers argue that the stem cell count contained in bone marrow is low (about seven stem cells per 100,000 total cells) and best suited to make various kinds of red and white blood cells, not fibroblasts. If you really want to call on the powers of stem cells to heal ligaments and tendons, they say, you should harvest them from a bit of tissue the horse won’t miss, culture them in a lab to increase their numbers several million-fold, and then re-introduce them to the injury site.
This approach is being used with considerable success by Vet-Stem Inc. in Poway, California, as well as in Australia and multiple other sites around the world. Robert Harman DVM, MPVM, who founded Vet-Stem in 2002, has found that stem cells can be neatly harvested from ordinary adipose (fat) tissue near the horse’s tailhead -- a procedure considerably simpler and safer than harvesting bone marrow from the sternum. All a veterinarian need do is send about two tablespoons of fat tissue from the injured horse to the Vet-Stem lab by courier. There, the stem cells will be isolated and concentrated over the course of a few hours. Then they can be sent winging back to the vet by return courier, to be injected into the injured tissue.
Pioneers in stem cell therapy thought it was necessary to stimulate the stem cells in vitro to become the type of mature healing cells needed to heal the targeted injury - but it turns out that it’s more effective to let them stay stem cells. According to Harman, the cells have an uncanny ability to detect the type and location of an injury in the horse’s body, and let the local tissue damage dictate their future. If introduced to an injured tendon, they make new tendon fibres; injected into the heart, they would make new heart muscle; and added to a fracture site, they transform themselves into osteoblasts and make new bone.
In the case of tendon and ligament injuries, the end result of some injected stem cells is a beautifully healed, more elastic structure with less scarring and more potential for returning to peak performance. Harman emphasizes it’s not a shortcut - the healing is more complete, but not faster. And the best time to initiate this type of therapy, he says, is after the initial inflammation has receded, but before scar tissue begins to form; in other words, sometime between day seven after injury, and day 28. Stem cell therapy has demonstrated some ability to stimulate healing in older injuries which haven’t responded to other methods, but the best results come with earlier action.
We’re only beginning to tap the immense potential of stem cells. With their ability to assist healing in virtually any kind of tissue, it’s easy to imagine the possibilities. Someday soon, stem cells might be used prophylactically, to help racehorses deal with the everyday wear and tear on their tissues before they become major injuries. And since stem cells freeze and thaw easily in liquid nitrogen, they could be harvested and banked for a horse’s future treatment.