Why bucked shins are so prevalent in the racehorse
/Article by Adam Jackson MRCVS
One of the most common causes of lost days to training and racing in racehorses is dorsal metacarpal disease (DMD), often referred to as “bucked shins” or “sore shins.”
Often a frustration to trainers and owners, this problem rears its ugly head at the time of highest expectations, such as arising the last day of work before a horse’s first race, right after a horse’s first victory or after a horse was purchased at a two-year-old sale.
This disease presents with heat, pain with or without inflammation (swelling) on the dorsal (front) surface or the dorsomedial (front inside) surface of the third metacarpal bone (cannon), which is referred to as acute periostitis. With rest and reduced exercise, the condition can improve, but catastrophic fractures of the cannon may occur at the site of previous DMD episodes. A good understanding of this disease and strategies of prevention are vital in order to improve the welfare of the horse and reduce the potential expenses to all shareholders.
Introduction
The cannon bone is an important structure in the weight bearing and absorbing shock. As the horse moves, the bone bends a little and then returns to its original shape like an elastic band, which is often referred to as elastic deformation. In addition, it has been observed that horses that work slowly have tension on the front of the cannon bone; in other words, the bone is stressed by a stretching force rather than a compressing force. However, at higher speeds, these forces change from stretching to compressing forces.
Repeated bending forces (stress cycle) on the cannon bone causes dorsal metatarsal disease. When the horse is young, it has a thin bone cortex. As the horse grows and is repeatedly subjected to these forces, the bones remodel and the cortex thickens, making it stronger. However, if the bending forces exceed the bone’s ability to remodel, then this leads to stress fatigue and bone damage.
The occurrence of bucked shins is most common when horses are developing, typically at two to three years old as training becomes more intensive. But it must be noted that if the horse is not bone fit, any aged racehorse is susceptible to these diseases when they begin training. Roughly at the age of five years, when a horse is fit, they are at a low risk of this disease. Within the first six months of training, DMD may present in one or both front limbs. If the condition does occur in both front limbs and the horse is being trained on a circular track, then it is likely the inside leg is where it will occur first. In other words, if the training tends to be in a counterclockwise training circuit, then there are greater forces on the left limb than the right, thus the left is more likely to develop the disease before the right limb.
Risk Factors of DMD
Age: DMD occurs most commonly in two to three-year-olds often within their first six months of training. It is rarely seen in horses with a mature skeleton (age four and over). However, this disease has been seen in five-year-olds especially if they have been stalled for a long amount of time after weaning and not racing until that age.
Gender: It is believed that the gender of the horse does not alter its risk to DMD.
Breed: Most common in Thoroughbreds but may be seen in both Standardbreds and Quarter horses.
Genetics: The risk of DMD is influenced by genetics as variation in limb bone geometry (inherited) behaves differently to force/strains on the bone. In addition, the longer the cannon bone, the greater the load is at flexion of the dorsal cortex of the bone, making it more susceptible to DMD.
Training and racing surfaces: The different types of training and racing surface alter the risk to DMD because there are variations in the force applied to limbs as well as the acceleration rates of hoof impact. Furthermore, the impact of these forces is increased with greater speed. Dirt tracks tend to be the hardest surface, whereas synthetic tracks reduce hoof and limb impact and loading force. However, it is important to remember that the hardness all of these surfaces can be altered by a number of other factors such as:
Training and racing surfaces
Different surface materials
Changes in weather, temperature and humidity
Surface maintenance (i.e., soaking, harrowing)
Changes in horse body weight
Age of surface, wear and tear of surface
Human opinion of condition of track
6. Training: The length of time for bones to respond to different training practices is unknown. Although further research is required, it is suggested that fast work should be avoided in the early stages of training as it is thought that high-speed exercise introduced too quickly (within one month) was detrimental to bone health.
7. Direction of training: Track direction varies globally. Thoroughbreds tend to lead with the inside forelimb around turns then switch to the outer forelimb on the straight. It has been suggested that due to greater forces on the leading limb on the turn, that limb is more at risk of bucked shins. However, more research is required to make accurate conclusions.
8. Speed: Current research is contradictory. Some research indicates a reduction in the risk of DMD if the horse is trained at high speeds with every extra mile worked, and canter work increases the risk. However, other research suggests that short periods of work (< 1 month) at high speed increases the risk of DMD.
9. Camber: In the U.S., tracks are usually flat in contrast with European tracks, which tend to vary in their design and often include slopes, twists, turns, uphill sections, and cambers, with turf being the prevalent surface. In addition, races may be run straight, clockwise or counterclockwise. Although it is known that this variation in track characteristics alters the horse’s gait, thus altering forces on the forelimbs, further research is needed to understand if these variations increase the risk of DMD.
How does DMD develop?
Bucked shin is the formation of tiny stress fractures on the front or inside of the cannon bone of the horse’s front legs. DMD occurs when the stress on the legs with high-speed training exceeds the bone’s ability to adapt to those stresses.
Bone is a dynamic tissue that is constantly adapting its structure. Once the bone is formed in immature animals, the bone grows and changes shape by a process called modeling. Bone remodeling is different to modeling in that its function is to renew the skeleton and involves both bone resorption and formation to occur at the same location in a sequential manner.
With high-speed training, there is high-strain fatigue, which causes excessive compression of the bone. During this compression, there is an insufficient amount of bone remodeling at the point of stress. At this site, this new bone is much weaker; thus, it is susceptible to inflammation, and pain and may lead to fractures.
Treatment of dorsal metacarpal disease
Treatment of DMD is designed to alleviate pain and inflammation while allowing the remodeling process of the bone to catch up with the damage that has been caused from stress cycling.
The core of the treatment is rest and providing pain relief, followed by a slow and gradual increase in exercise levels.
Fractures of the bone cortex can be treated with surgery using lag screw fixation and osteostixis. Osteostixis is the drilling of many holes around the site of fracture in order to promote bone healing. Lag screw fixation is the drilling of a screw across the fracture line to compress and stabilize the bone. However, fracture recurrence is common with both techniques and requires five to six months out of training.
There are additional treatments that may be used to complement core treatments. Extracorporeal shock wave therapy (ESWT) is commonly used for treatment and involves a highly concentrated, powerful acoustic (sound) energy source being applied to the site of injury. The rationale is that ESWT increases blood flow, increases growth of new blood vessels and increases the production of natural healing factors in the treated area. The research findings are limited on its effectiveness but anecdotally among the veterinary profession, it seems to work on bucked shins and stress fractures.
In North America, horses are not permitted to race or breeze for 30 days following treatment as per the Horseracing Integrity and Safety Authority’s (HISA) rulings. In Europe, horses must not have had shock wave therapy on the day of racing, or on any of the five days before the race day in which the horse is declared to run.
With all treatment options, there must be a careful and considered discussion with the veterinarian and all stakeholders on the desired outcome while bearing in mind the important factor of the horse’s welfare and wellbeing.
What about bisphosphonates?
Some clinicians are using a combination of shockwave and bisphosphonates (TildrenTM, OsPhosTM) to treat DMD. Bisphosphonates were first seen in human medicine and used for osteoporosis. Bones are constantly remodeling in a process that removes old bone cells and deposits new ones. Bisphosphonates help prevent bones from losing calcium and other minerals by slowing or stopping that natural process that dissolves bone tissue, thus, helping bones remain strong and intact. Veterinary surgeons report mixed results with these therapies, and long-term use of bisphosphonates is expensive and has serious consequences. Bisphosphonates are toxic to the gastrointestinal and renal systems, thus, potentially causing colic and kidney disease. Their safety has not been evaluated for the use in horses younger than four years old nor in pregnant and lactating mares.
RULES ARE CHANGING - Bisphosphonates
HISA’s Anti-Doping and Medication Control (ADMC) Program came into effect on March 27 and with it, new regulations regarding the presence and use of bisphosphonates.
The Horseracing Integrity & Welfare Unit (HIWU) states “The ADMC Program regulations categorize bisphosphonates as a banned substance, meaning that they are prohibited from being administered to, or present in, covered horses at any time. Covered horses that test positive for bisphosphonates under the ADMC Program are subject to lifetime ineligibility, and associated covered persons may incur an Anti-Doping Rule Violation.”
“HIWU will not pursue disciplinary action against Covered Horses or their associated covered person(s) for the presence of bisphosphonates if the covered person(s) can provide documentation (e.g., medical records or a positive test result) to HIWU of the administration or presence of bisphosphonates prior to the implementation date of the ADMC Program.”
In Europe, bisphosphonates are not to be administered to a racehorse under the age of three years and six months as determined by its recorded date of birth, on the day of the race or on any of the 30 days before the day of the race in which the horse is declared to run as per The International Federation of Horseracing Authorities rulings.
Training Regimens
With DMD, it must be remembered that it is an appropriate response for new bone formation when the cannon endures cyclic stress and injury. This injury cannot be ignored but addressed to reduce the risk of serious consequences. Exercise is the root of the problem; therefore, the solution is to alter the patterns of exercise.
Dr. David Nunamaker, DVM, of the University of Pennsylvania, has developed a training program, which is believed to reduce the risk of DMD. The rationale when developing this modified training program is that horses are not born with the right bone structure for racing. The bones are to develop and adapt to racing. By providing training programs that mimic racing, the bones can adapt to the forces that are applied during racing, thus, reducing the risk of developing bucked shins.
When initiating this training regimen, it is assumed that young horses are broken to ride in autumn and able to gallop a mile by January so that training can start.
Stage 1 (5-week duration) – Horses finish the gallops two times a week with the last 1/8th of the mile (last 200 meters of 1600 meters) completed in an open gallop in 15 seconds.
Stage 2 (5-week duration) – Twice a week, open gallops for ¼ of a mile (400 meters of 1600 meters) in 30 seconds including a one-mile (1600 meters) gallop.
Stage 3 (7-week duration) – The addition of speed work once per week. Breezing (moderate speed) for ¼ mile (400 meters) and daily gallops lengthened to 1¼ miles twice per week for four weeks. In the following three weeks, the ¼ mile breeze is continued with a strong gallop out for another furlong (roughly 40 seconds total for a breeze).
Conclusion
The findings of exercise research are often varied and contradictory due to many research variables, making comparisons and conclusions difficult. In addition, most of the research of musculoskeletal issues in racehorses uses racing data, but most injuries occur during training.
Because more research is needed, there remain conflicting views of the effects of racing on horses before skeletal maturity and the most effective and safe way to introduce speed exercise. At present, the data suggests that distance and speed should be implemented gradually and should include high-speed work at full racing speed.
The racing industry must continue to work cooperatively to address the welfare concerns associated with horses experiencing DMD.
![Life After LasixWords: Denise SteffanusAn estimated 95% of American racehorses go postward on Lasix, a diuretic that reduces bleeding in the lungs caused by extreme exertion. Now, nearly 50 years since horsemen and veterinarians battled for approval to use the therapeutic drug on race day, stakeholders in the industry have launched an initiative to phase out Lasix from American racing.The debate whether Lasix, technically known as furosemide, is a performance enhancer or a performance enabler has raged for decades. With that debate comes the discussion whether Lasix helps the horse or harms it. But we’re not going to get into that debate here.With racetrack conglomerates such as The Stronach Group and Churchill Downs adopting house rules to ban Lasix use on race day in two-year-olds starting this year and in stakes horses beginning 2021, the political football of a total Lasix ban for racing is headed to the end zone. Whether that total ban happens next year or in five years, racing needs to take an objective look at how this move will change the practices and complexion of the industry at large. The Lasix ban will affect more than what happens on the racetrack. Its tentacles will reach to the sales ring, the breeding shed, the betting window, and the owner’s pocket.When Lasix first was approved for racing in 1974, only horses that visibly bled out the nostrils—an extreme symptom of exercise-induced pulmonary hemorrhage (EIPH)—were permitted to use the drug. A few years later, flexible endoscopes enabled veterinarians to identify horses with trace levels of EIPH internally that qualified them for Lasix. So many horses became approved for Lasix that most jurisdictions stopped requiring proof of EIPH to send a first-time starter postward on Lasix. All trainers had to do was declare it on the entry. Soon, nearly every horse was racing on Lasix, many with no proof it was needed. And that’s the situation we have today.Racing regulations tag a horse as a bleeder only if it visibly hemorrhages from one or both nostrils (epistaxis). For this article, “bleeder” and “bleeding” are general terms for all horses with EIPH, not just overt bleeders. With almost every horse now competing on Lasix, no one knows how many horses actually need the drug to keep their lungs clear while racing. When Lasix is banned, we’ll find out.Safety FirstHow a particular horse will react when capillaries in its lungs burst is unpredictable. Thoroughbreds are tough, so most horses will push through the trickle, and some may win despite it. Other horses may tire prematurely from diminished oxygen, which could cause them to take a bad step, bump another horse, or stumble. Fractious horses with more severe bleeding may panic when they feel choked of air. Will the current number of human and equine first-responders be adequate to handle the potential increase in these EIPH incidents?Racing Hall of Fame rider Mike Smith, who earned two Eclipse Awards as outstanding jockey, has ridden in more than 33,000 races during his four decades on the track. He said he can feel a change in the horse under him if it begins to bleed.“Honestly, a lot of times you just don’t see that ‘A’ effort that you normally would have seen out of the horse,” he said. “You know, they just don’t perform near as well because of the fact that they bled, which you find out later. … When they bleed enough, they can literally fall. It can happen. It’s dependent on how bad they bleed. If a horse bleeds real bad, they don’t get any oxygen. … I’ve been blessed enough to have pulled them up, and if I wouldn’t have, they probably would have gone down or died, one or the other, I guess. They’re few and far between when it’s that bad, but it does happen.“If you literally see the blood, then you stop with them. You don’t continue because it’s very dangerous.”In 2012, Dr. Tom Tobin, renowned pharmacologist at the University of Kentucky’s Maxwell Gluck Equine Research Center, and his colleagues reviewed the correlation between EIPH and acute/sudden death on the racetrack, as set forth in published research. They noted that 60%-80% of horses presumed to have died from a “heart attack” were found upon necropsy to have succumbed to hemorrhaging into the lungs. Tobin and his colleagues concluded their review with a warning: “EIPH-related acute/sudden death incidents have the potential to cause severe, including career-ending and potentially fatal injuries to jockeys and others riding these horses.”Mark Casse has won 11 Sovereign Awards as Canada’s outstanding trainer, five Breeders’ Cups, and three Triple Crown races. He’s a member of the Horse Racing Hall of Fame in both Canada and the United States, one of just three individuals to accomplish that feat (Lucien Laurin and Roger Attfield are the others).“If as soon as they ban Lasix, we start having more injuries, they’re going to have to do something about that,” Casse said. “It will be more than just first-responders. That’s pretty scary to think, ‘Ok, we’re going to take horses off Lasix, and so now we’re going to need more medical people out there.’ That doesn’t sound too good to me.”Training StrategiesCasse has a special way of training horses with EIPH, but he was cagey about the details and reluctant to disclose his strategy.“What I do is try to give any horse that I feel is a bleeder, especially four to five days into a race, a very light schedule,” he said. “That’s one of the main things I’ll do with my bad bleeders. So, in other words, not as much galloping or jogging—stuff like that.”In 2018, trainer Ken McPeek had the most U.S. wins (19) without Lasix. Besides racing here, McPeek prepares a string of horses to race in Europe, where Lasix is not permitted on race day. He puts those horses on a lighter racing schedule.“As long as a horse is eating well and doing well, their chances of bleeding are relatively small,” he said. “If a horse is fatigued and stressed, I always believed that would lead to bleeding.”McPeek said if a two-year-old bleeds, the owner and trainer are going to have a long-term problem on their hands, and they’re better off not racing at two.In 2012, the first year the Breeders’ Cup banned Lasix in two-year-olds, Casse’s rising star Spring in the Air entered the Grey Goose Juvenile Fillies (Gr1) fresh off an extraordinary effort in the Darley Alcibiades Stakes (Gr1), where she lagged behind in tenth then launched an explosive four-wide dash coming out of the turn to win by a length.The filly had run all four prior races on Lasix, but without Lasix in the Juvenile Fillies, she never was better than fifth. After the race, Casse told reporters she bled.“She went back on Lasix,” Casse said of Spring in the Air, who became Canada’s Champion 2-Year-Old Filly that same year.Dr. Jeff Blea is a longtime racetrack veterinarian in California and a past president of the American Association of Equine Practitioners. He said racing without Lasix is going to require a substantial learning curve for trainers and their veterinarians. During this interview Blea was at Santa Anita Park, where he’s been working with trainers to figure out the best way to manage and train horses that race without Lasix.“That’s a case-by-case discussion because all trainers have different routines and different programs,” he said. “In addition to the variability among trainers, you have individual horses that you have to factor into that conversation as well.”When a horse comes off the track from a work or a race with severe EIPH, Blea asks the trainer if this has happened before or if it’s something new. If it’s new, he looks at the horse’s history for anything that could have precipitated it. Blea uses ultrasound and X-rays to examine the horse’s lungs.“With ultrasound, I can often find where the bleed was,” he said. “If I X-ray the lungs, I’ll want to look for a lung lesion, which tells me it’s a chronic problem. I want to look at airway inflammation and the overall structure of the lungs. … I’ll wait a day and see if the horse develops a temperature. I’ll pull blood [work] because this bleed could be the nidus for a respiratory infection, and I want to be able to be ahead of it. I typically do not put horses on antibiotics if they suffer epistaxis, or bleed out the nose. Most times when I’ve had those, they don’t get sick, so I don’t typically prophylactically put them on antibiotics.”Based on his diagnostic workup, Blea will recommend that the horse walk the shed row for a week or not return to the track for a few weeks.“Depending on the severity of my findings, the horse may need to be turned out,” he said. “I use inhalers quite a bit. I think those are useful for horses that tend to bleed. I’m a big fan of immune stimulants. I think those are helpful. Then just old-fashioned, take them off alfalfa, put them on shavings...things like that.”Blea discusses air quality in the barn with the trainer—less dust, more open-air ventilation, and common sense measures to keep the environment as clean and healthy as possible.Prominent owner Bill Casner and his trainer Eoin Harty began a program in January 2012 to wipe out EIPH in his racehorses. Casner's strategy to improve air quality for his horses and limit their exposure to disease is to power-wash stalls before moving into a shed row and fog them with ceragenins—a powerful, environmentally safe alternative to typical disinfectants. He has switched to peat moss bedding, which neutralizes ammonia, and he only feeds his horses hay that has been steamed to kill pathogens and remove particulates.Particulate MappingActivities in barns, particularly during morning training hours, kick up a lot of dust. Researchers at Michigan State University looked at particulates (dust) that drift on the air in racetrack barns. Led by Dr. Melissa Millerick-May, the team sampled the air in barns and mapped the particulate concentration in a grid, documented the size of the particles, identified horses in those barns with airway inflammation and mucus, then correlated the incidence of airway disease with hot spots of airborne particulates.For part of the 18-month study, the research team used hand-held devices to assess airborne particulates; another part outfitted the noseband of each horse's halter with a device that sampled the air quality in the horse's breathing zone.Some stalls appeared to be chronic hot spots for particulates, and horses in those stalls chronically had excess mucus in their airways. Often, moving the horses out of those stalls solved the problem.These hot spots were different for each barn. Interestingly, because small particulates lodge deep in the lungs more easily than large ones, a stall that visibly appears clear might be an invisible hot spot.Getting Prepared for the Pegasus—Lasix-FreeDr. Rob Holland is a former Kentucky racing commission veterinarian based in Lexington who consults on infectious disease and respiratory issues, for which he obtained a PhD. Months prior to the Lasix-free Pegasus World Cup Invitational Stakes at Gulfstream Park in Florida, several trainers asked his advice on how to condition their horses so they could compete without Lasix. He told them they needed to start the program at least six weeks before the race. His first recommendation was to use ultrasound on the horse’s lungs to make sure they didn’t have scarring, which is a factor in EIPH, because scar tissue doesn’t stretch, it rips. Scarring can develop from a prior respiratory infection, such as pneumonia, or repeated episodes of EIPH. Next Holland directed the trainers to have the horse’s upper airway scoped for inflammation and excess mucus.“I had one trainer who scoped the horse’s upper airway and trachea and decided, with the history of the horse, against running in the race without Lasix,” Holland said. “So there were trainers who were really on the fence, and that was for the betterment of the horse. Every trainer I talked to, that was their main focus: How do I do this so that my horse is OK? That was always the first question they would ask me. Second, they would ask me if I could guarantee [that] running their horse without Lasix wouldn’t cause a problem, and the answer is there’s no guarantee.”Holland instructed trainers to start cleaning up the horse’s environment at least six weeks before the race to rid the air of dust, allergens and mold. He told them not to store hay and straw above the stalls; remove the horse from the barn while cleaning stalls and shaking out bedding; don’t use leaf blowers to clean the shed row; don’t set large fans on the ground in the shed row; elevate them so they don’t stir up dust; practice good biosecurity to avoid spreading disease; and steam or soak the horse’s hay and feed it on the ground. All this reduces irritation and inflammation in the airway.Holland prescribed nebulizing the horse’s lungs twice a day either with a chelated silver solution that kills microorganisms or ordinary saline solution to soothe the airway. He cautioned trainers with allergic horses not to use immunostimulants, which might cause adverse reactions in them.By starting the program well in advance of the race, trainers were able to experiment with management and training strategies to see which worked best.“We programmed all the horses to be ready for a race without Lasix by starting the program at least a month before the race,” Holland said. “We tried to simulate the exact situation they’d be going into at Gulfstream—same bedding, same feed, same hay, but no meds. If the horses didn’t have a problem, they could give their best. Also, I wanted the trainers to test the theory that the horse could do OK in a work without Lasix. So the horses all worked and got scoped afterward to see that there weren’t any issues before the Pegasus. The trainers followed my advice, and they knew their horses would be OK. And they were.”Confidentiality prohibited Holland from identifying the trainers who consulted him, but he said all their horses ran competitively in the Pegasus with only trace amounts of bleeding or none at all.Help Us, PleaseSome horsemen have expressed frustration, complaining that racetracks are telling them they have to race without Lasix, but they’re not telling them how to accomplish this or helping them implement the change. Continuing education focuses mostly on reducing breakdowns, but it offers no modules to help trainers understand and deal with EIPH—arguably the hottest topic in racing.Just prior to the Pegasus in January, The Stronach Group rolled out its new brand, 1/ST Racing, and named Craig Fravel its chief executive officer. His task is to manage and oversee racing operations at all Stronach Group-owned racetracks and training centers. Fravel came to 1/ST (pronounced “First”) after serving eight years as CEO of the Breeders’ Cup.Fravel said he wasn’t aware of the horsemen’s frustration.“I’m happy to jump into that and make sure that our communication with them in terms of best practices and concepts is addressed,” he said, vowing to have Dr. Rick Arthur, equine medical director for the California Horse Racing Board who helped develop the Jockey Club’s continuing education modules, look into adding information about EIPH and racing without Lasix.Fravel also wants horsemen to know that 1/ST is dedicated to improving air quality on the backside.“Ventilation and dust control is a big part of eventually weaning the horse population from Lasix, and we’re certainly willing to look at that and figure out ways we can improve the overall ventilation and conditions for the horses,” he said.Fravel voiced an interest in Michigan State’s particulate mapping and said he planned to follow up with Dr. Millerick-May.Gulfstream Park has erected three “tent barns” that are large and airy with high ceilings and fans near the top. At Palm Meadows Training Center about 40 miles from Gulfstream, plans include building tent barns to house 300-400 new stalls.“The one thing about Florida racing is that all our barns are basically open,” said Mike Lakow, vice president of racing for Gulfstream Park. “It’s not enclosed barns as in the Northeast where weather is an issue.”Fravel said the same of Santa Anita’s barns.“They’re in a nice, breezy environment where much of the barn area is much more outdoor oriented than you would find on the East Coast,” he said. “Then at Laurel [Park in Maryland] we also have long-term plans for the entire barn area, which should be completed—if the current planning continues to take effect—in roughly two years’ time.”So Far, So GoodWithout knowing how many horses will be able to race competitively without Lasix and how many will be lost through attrition because their owners decide to stop on them, filling races and field size becomes a question. Lakow said this hasn’t been an issue so far.“As far as our two-year-old races at Gulfstream Park this year, we’ve had close to 25 without Lasix, and field size has not diminished at all,” he said going into the 4th of July weekend. “…With the Stronach Group deciding to run our two biggest races, the Pegasus World Cup and the Pegasus World Cup Turf in January without Lasix, we had full fields, and I really didn’t hear issues of horses bleeding from those two races.“Now, granted, we invited every top dirt horse and turf horse in the country, and I would say less than 5% said they couldn’t participate because there was no Lasix.”(NOTE: The California Horse Racing Board and Churchill Downs were given the opportunity to speak to horsemen through this article but declined. The New York Racing Association did not respond.)Handicapping: No More Speed in a BottleA first-time Lasix horse always has been the bettors’ Golden Ticket, especially when it was inside information not printed in the program. For decades, astute handicappers have studied how individual horses react when racing on Lasix or without it. That’s all about to change.Paul Matties Jr., who earned the 2016 Eclipse Award for handicapping, calls Lasix “speed in a bottle,” and he knows most people are going to take that the wrong way. Matties believes a horse keeps itself together better when it races on Lasix, giving the jockey instant speed at his fingertips.“It’s more of a sustained run,” Matties said. “They’re going to have to work more for it instead of just asking. Modern jockeys have been used to this. I ask and the horse will give it to me because it’s speed in a bottle. It’s canned speed. And I believe a lot of that is because of Lasix.“Jockeys nowadays know they have it, so it’s more about relaxing the horse and getting into a rhythm. They don’t have to worry about the speed part. I think as they get off Lasix, they’re going to have to worry about that more. It is going to be different, and I think the jockeys will notice the difference.“As far as handicapping, the one thing that definitely is going to happen in dirt races is that speed will do better. It’s going to go against what people think in general. But I think the horses that don’t get the lead will be the ones that will bleed more. I don’t think it will happen every race, obviously. But, in general, I think speed will do a little bit better. I think the Lasix keeps the horses together longer, where they’re able to sit chilly as long as they can and have an explosive run. They will have less of that ability to do that. I will definitely look for horses near to the lead.”Buyers, Sellers and BreedersBloodstock agent Gayle Van Lear believes EIPH could become an undesirable trait that buyers and breeders will avoid. Horsemen will need to start paying attention to those horses racing now to see if they perform poorly when they don’t receive Lasix. Then they will have to decide if they want to breed to them when they retire from racing. In the not-so-distant future, will certain bloodlines fizzle out on the track because they inherited a predisposition to EIPH?“That’s like anything that falls on the same line, like all the Storm Cats that had offset knees and all the crooked Mr. Prospectors,” Van Lear said. “Those, over time, phase themselves out through the gene pool, and the chips fall where they fall. So I don’t see this as being any different. It’s just going to be that those horses that are very bad bleeders genetically will phase themselves out of the gene pool because they are not going to be competitive.”For now, it is a guessing game as to which current stallions and mares might produce bleeders.In 2014, a group of Australian researchers at the University of Sydney published a 10-year study to determine if horses could be genetically predisposed to epistaxis. The study reviewed 1,852,912 individual performance records of 117,088 racehorses in Australia, where Lasix is banned for racing. As part of that study, the researchers investigated the pedigrees of 715 sires and 2,351 dams.“Our research showed that epistaxis is moderately heritable,” co-author Dr. Claire Wade, professor and chair of Computational Biology and Animal Genetics, said in an email. “This implies that it is a complex trait that can be selected against in a breeding population. Exercise-induced pulmonary hemorrhage (EIPH) is the underlying condition that, when severe, manifests as epistaxis. That epistaxis is inherited implies that EIPH is also inherited. The inheritance is not a simple Mendelian trait [dominant, recessive], and so it is unlikely to be controlled by DNA-based testing. Because horses with epistaxis are less successful on the racetrack in the long run, there should be selection against the disorder. I expect that this is more likely to be achieved by indirect selection against breeding stock through their exclusion from racing than by bloodstock agents avoiding purchase of animals with epistaxis in their pedigree.”Wade’s co-author and emeritus professor of Animal Genetics, Dr. Herman Raadsma, agreed, adding, “Although heritable, a significant component is non-genetic or chance occurrences for reasons we may not necessarily know why or predict in advance.”Kevin McKathan, who since 1988 has operated McKathan Brothers Training Center and bloodstock agency with his now late-brother J.B., said what he looks for in a horse probably isn’t going to change.“When I buy or sell horses, I would say maybe it’s a 10%-15% possibility that you end up with a true bleeder,” he said. “Until we have the data that shows the mare was a bleeder, the stallion was a bleeder, the mare’s mother’s mother was a bleeder, I’m not sure how we could make that decision on their genetics,” McKathan said.“If you’re buying a horse that’s already racing on Lasix, that would definitely be a concern. But I think we’re going to have to figure out a way, if they ban Lasix, to get along with those horses that have breathing problems. Hopefully, you won’t get one.“I don’t believe we breed bleeders necessarily,” McKathan continued. “I believe certain horses are traumatized, where they do bleed; but I believe with a different training method, there’s a possibility that these horses won’t bleed. So we’re going to have to learn how to train around that problem if they take Lasix away from us.”Dr. Robert Copelan, 94, was the track veterinarian for Thistledown near Cleveland in the 1950s, before Lasix was approved for race day. Part of his job was to observe every horse during unsaddling after a race and enter the names on the Vet’s List of horses that visibly bled.“The riders sometimes would come back with blood all over their white pants and their silks, just a horrible sight to see, right in front of the grandstand where they took the saddles off those horses,” he recalled.Copelan estimated 1%-3% of those pre-Lasix runners would end up on the Vet’s List, which required trainers to lay them off for a certain number of days and then demonstrate they could breeze a half-mile for Copelan without bleeding. Every additional incident of bleeding within a 365-day period for that same horse increased the mandated time off. For the third or fourth incident within a year, depending on the jurisdiction, the horse would be ruled off for life. These bleeder regulations still exist in every jurisdiction.Copelan is concerned about these horses and the horsemen who invest in them.“Let’s say you and I have teamed up in a partnership and we’re going to buy a couple of horses, and we’ve had good luck together,” he said. “Now we’re interested in a horse, and we’re going to have to give between $850,000 and a million for him. We buy him, and now when he turns two and we have him ready for his first race, the son of a gun turns out to be a bleeder. Are we going to sit there and say, ‘Oh, what bad luck!’?”Prospective buyers can examine sale horses for imperfections, such as throat abnormalities and those that potentially could cause lameness, but there is no way to tell if a horse will be a bleeder. When examined, any damage found in the airway and lungs from a prior respiratory illness sets off warning bells, but with no guarantee the horse will develop EIPH when it races. Every fall of the hammer becomes a roll of the dice for these buyers.Terry Finley, president of West Point Thoroughbreds, said the scenario Copelan described is an unfortunate situation, but he doesn’t know how often one could reasonably expect it to happen.The owner’s responsibility will be to decide what to do about horses with EIPH. Management changes, added preparation, veterinary care before and after a race, and time off to allow the horse’s lungs to heal all add up to larger training and veterinary bills. Many owners will have to take a hard look at the long-term plan for horses with EIPH that can’t be competitive without special handling. Is the added expense worth it, or should they retire the horse? It’s unlikely to be desired as breeding stock, even with a stellar pedigree. What happens to it then?“The more I talk to people all around the country, they see this situation, while not perfect, as a compromise,” Finley said of the move to ban Lasix. “They see it as a way to move past this issue, at least in the short term, and they understand that it’s not going to be perfect. I’ve thought about this a lot, and I’ve talked to a lot of people. If you look at it at the fringes, it could present some problems. But, by and large, the hope is that this is going to be better for the greater good, and that’s what we hope will be the situation at some point in the future.”](https://images.squarespace-cdn.com/content/v1/517636f8e4b0cb4f8c8697ba/1596789747311-JB0OSD4DJHZAXIIZVZ7R/Z200125_eclipsesportswire__04580+%281%29.jpg)
