June 11, 2008, New York Times, The Rail
Horsemanship and Horse Racing
By SID GUSTAFSON
I have to be careful writing about jockeys and riding as I still do veterinary regulatory racetrack work from time to time representing the horses and jockeys safety and welfare on race day. I try to stay out of debates involving riding strategy, so as not to have jockeys lose confidence in me should I happen to perform regulatory work at their track in the future. In order to effectively carry out regulatory duties, veterinarians have to maintain trusting working relationships with the jockeys. On the other hand, proper horsemanship is essential for horse racing safety, and regulatory veterinarians are certainly responsible for that.
I teach natural horsemanship at the University of Montana Western, where I have the good fortune to ride in all of the horsemanship classes. We study the nature and behavior of horses and base our training on this understanding of horses.
After the gate opened in the Belmont Stakes, Kent was dealing with a Big Brown anxious to sprint to the lead. Brown seemed to shy sideways to the right away from the starter standing in the track after he slipped out of the gate. Kent reacted and Brown did not respond to the rider’s initial reaction and instruction like Kent had anticipated, and the rider had to apply a large amount pressure to the reins, repeatedly, wrestling the horse in one direction then the other. The early issues between horse and rider cascaded, and the partnership between horse and rider deteriorated out of the gate well into the first turn.
It seemed that the Brown team knew that a deficit in the connection between Kent and Brown existed when they last observed Kent gallop Big Brown. It was reported by the trainer through the media that the horse was all over the place on a morning gallop with Kent aboard.
The general horsemanship belief is that once a horse gets his way with an unassertive rider through the course of a gallop, the horse will attempt to have its way with the rider on future rides by ignoring the cues the rider gives with the reins and legs. According to the news media and Dutrow, Brown got the best of Kent the last time Kent galloped him. Kent was not able to get Brown to respond to his cues on the gallop.
Apparently, the trainer observed the horse get his way with Kent on the last gallop and did not take measures to correct the racehorse’s relationship with the rider before the race. Subsequently, the horse did not respond to Kent in the race. In essence, Kent had to retrain the horse to respond to his cues through the first quarter mile.
If Brown understood he could get away with refusing to answer to Kent’s cues appropriately on gallops, Brown is not going to react any better to Kent’s cues in a race.
Dutrow’s description of Kent’s last gallop of Big Brown seemed to match the subsequent race ride Kent gave Brown, which is what horsemanship studies would expect, and even predict. In trying to find answers as to what might be done differently to prepare Big Brown for future races with Kent up, the horsemanship issues between horse and rider regarding response, connection, and communication need refined before the race.
Nothing is simple in horseracing, and most race finishes are the result of many, many factors and sequences of factors. Horses’ reaction times are lightning quick. However practiced, a human’s reaction to a horse’s reaction is not always a rhythmic thing when extenuating pressures and surprises arise, or when preparation has been lacking. In retrospect, it now seems that it may have been inappropriate to let Brown get away with a disobedient gallop with Kent up before the race. Brown also could have been better prepared mentally for the race, so to have been in a partnering mood with his rider. This is of course all very complex, and horses regularly fool horsemen. Developing a better understanding of equine behavior is the goal of all horsemen, but much of our learning is trial and error.
I do not share these horse behavior observations to place blame, but to clarify an aspect of horse training and memory. Certainly, losing the race was not Big Brown’s fault. He is in the hands of people, the training, the riding, the conditioning, the medication; everything the horse does is at the hand of man.
In natural horsemanship, we teach that the horse is never wrong. Riders have to develop partnerships of confidence, respect, and connection with each horse they ride, and consistently maintain all aspects of those partnerships to ensure a responsive partnership. If people are not consistent with horses, horses will not be consistent for people.
Not only was Big Brown unwilling to respond evenly for his rider, Desormeaux, Big Brown did not work as evenly as hoped for his regular exercise rider, Michelle Nevin, before the race. Horsetraining is in order for Big Brown, refinement of the basics of confidence, respect, and connection going both ways between horse and rider, all Brown’s riders. The owner and trainer’s idea to resume medicating Big Brown with Winstrol is a mistake, as anabolic steroids are notorious for making horses less trainable and responsive. Big Brown needs to get more connected with his riders, and anabolic steroids can contradict that goal.
If Desormeaux rides Big Brown in the coming races, the horsemanship issues between the horse and rider should be refined so that the horse and rider connection is more secure when the Haskell or Travers roll around.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
Horse Health Veterinary Consults with Dr Gustafson
California, New York
Thursday, June 12, 2008
About Those Steroids and Big Brown
June 10, 2008, 8:02 am
About Those Steroids and Big Brown
By SID GUSTAFSON
Lack of steroids did not appear to be the reason Big Brown tanked the Belmont. I went over the reasons I thought were significant in my last article. Big Brown is a stallion. Horses are seasonal breeders. Anabolic steroids are naturally occurring. As days lengthen the endogenous anabolic steroids, those produced internally by intact male horses, are increasingly secreted into their bloodstream.
The days have lengthened considerably since April. Whatever Winstrol was excreted or metabolized by Big Brown before the Belmont Stakes had by and large been replaced by race time with his increased secretion of seasonal anabolic steroids. By this time of year most stallions have established higher levels of androgenic steroids in their bloodstreams by secreting their own endogenous hormones in response to the lengthening days.
Although steroids can improve performance in horses, steroid administration in itself does not assure enhanced performance. Generally speaking, horses are adequately big, strong, and fast enough. Steroid administration is not always a beneficial thing, especially over the long run. There are adverse reactions and side effects aplenty. When the dosage is excessive, or sometimes even with small dosages, difficult behavioral issues often arise. The biggest problem is that horses become hard to manage and handle. They act rank. With horses control is essential to safety and performance. It seemed Big Brown was plenty frisky as he broke out of the gate for the Belmont. Behaviorally and physically, there appeared to be little appearance of a lack of steroids in the big horse’s system.
Since steroids can indeed at times improve performance for some horses, they should be banned. There is little doubt that life will be healthier and safer for racehorses when steroid use is restricted. Artificially enhanced performance means that some medicated horses will exert themselves more than they might without steroids, putting added stress on their legs and muscles, leading to more injuries than would be the case without the added juice. Additionally, there are significant deleterious side effects due to the injudicious use of anabolic steroids: subsequent sterility, cancer, heart disease, unhandleabilty, psychological confusion, and other troubles.
Are there justified medical uses for anabolic steroids in racehorses? Yes, but justified medical use does not include enhancement of performance beyond what would normally be a horse’s inherent ability. What then are anabolic steroids used to appropriately treat? Anabolic steroids are given to help horses recover from certain medical conditions involving weight loss, reduced appetite, and loss of muscle mass. There are also valid medical uses for anabolic steroids to help horses recover more quickly and heal stronger after undergoing arduous surgical procedures, prolonged stress, and racing and training injuries. Anabolic (building up the protein) steroids induce metabolic protein retention, resulting in the incorporation of additional protein into the muscular and other structural tissues, bulking up the horses and athletes on the stuff.
Any other uses? Well, yes. Horses that are given significant amounts of catabolic steroids may need anabolic steroids to allay the protein loss the catabolic steroids induce. Catabolic steroids or cortisone (those steroids that break down protein and cause it to be excreted) are often administered to race horses to reduce joint, bone, tendon, ligament, and muscle inflammation, as well as to treat a plethora of other medical, immune, and metabolic conditions (pulmonary disease, hypoglycemia, tying-up, allergies, and many other medical issues).
Joints are injected with cortisone, and cortisone is also given systemically (intravenously, intramuscularly) to be absorbed into the bloodstream. Anabolic steroids compensate for the deleterious side effects of cortisone injections. If the use of catabolic steroids is limited, this will eliminate the medical indication to use anabolic steroids to compensate. If the industry is going to move forward in the best interests of race horses, they should significantly limit the use of cortisone as well. This will level out the drug-playing field, and bring our medical racehorse morals up to the standard of the rest of the civilized world.
Are there other examples of where one drug needs another follow-up drug to compensate for the side effects of the original drug? Yes. Phenylbutazone (bute), in addition to its vaunted non-steroidal, anti-inflammatory effect, thins the blood, increases the clotting time, and can increase the potential for bleeding into the lungs during racing (exercise-induced pulmonary hemorrhage, EIPH). If we ban the bute, the horses hopefully won’t bleed as much, and we can then reduce the need for Lasix.
Without bute and other NSAIDs in the horse’s system, the racehorse will be less likely to bleed. Both anabolic and catabolic steroids cause fluid retention, which also increases the possibilities to bleed with the increased blood volume. Lasix, a diuretic and lung-blood-pressure reducer, is used to eliminate this excess fluid.
The horse racing industry could begin to restrict the original allowed drugs bute and cortisone, thus reducing the need for Lasix, anabolic steroids, antibiotics (steroids impair immunity) and other drugs which tend to be needed to mitigate the side effects of the original drugs.
The preference of many is that race horses should run clean. Drug-free racing is safer. It favors sound horses. Fewer drugs, then, allow horses to race sounder and longer, and drug-free racing might protect the horseplayers a bit. If horses are treated with the drugs veterinarians determine they need to be treated with, then the patients should not be allowed to race until the resultant therapeutic drug levels have subsided to insignificant levels.
Will this no-drug policy then push trainers to use drugs that cannot be detected? Yes again, but then attempts to gain advantage with drugs have always been problematic in horseracing. Legalizing the use of bute and Lasix drugs did not curtail this activity, it simply enhanced it. Allowable drugs “clouded” the tests, hiding other drugs. Lasix diluted illicit drugs in the urine, making them harder to detect.
The 35-year-old raceday-drug horseracing experiment has failed, or is failing. Too many fractures. Too many wrecks. Too many injured jocks. Too many down, dead horses. It is time to start running American racehorses clean like horsemen do in the rest of the world. The cleaner, the better. Racing jurisdictions gave veterinarians and trainers the go-ahead to use drugs liberally in the 70s. And, as is apt to happen with drugs, some individuals abused the dosages and administration of those drugs. They topped allowable drugs off with more drugs, and in doing so did their horses and patients and the thoroughbred industry a significant disfavor.
The ethical rule of equine veterinary medicine is this: First, do no harm. When drugs are implicated with harm, then it is time to re-evaluate their use. The argument that legal drugs somehow help horse racing is getting weaker and weaker. Legal drugs engender the use of more drugs. Some drugs may have their place in racing horses, but we need more evidence to overcome the contradictory evidence that drug use is diminishing the public’s confidence in horseracing.
We’ll never forget those images of Eight Belles trying to rise on two broken legs. None of those who witnessed that misfortune will, not even Big Brown. But that image will fade and be less-likely to be repeated if we all get together to make racing a more reasonable sport for the horses’ sake, for everyone’s sake. It is a good feeling to win a horse race with a thoroughbred, but the ultimate good feeling in horseracing comes when a horse runs clean, wins, and returns to the barn fit and sound. Let’s get that feeling going, now.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
About Those Steroids and Big Brown
By SID GUSTAFSON
Lack of steroids did not appear to be the reason Big Brown tanked the Belmont. I went over the reasons I thought were significant in my last article. Big Brown is a stallion. Horses are seasonal breeders. Anabolic steroids are naturally occurring. As days lengthen the endogenous anabolic steroids, those produced internally by intact male horses, are increasingly secreted into their bloodstream.
The days have lengthened considerably since April. Whatever Winstrol was excreted or metabolized by Big Brown before the Belmont Stakes had by and large been replaced by race time with his increased secretion of seasonal anabolic steroids. By this time of year most stallions have established higher levels of androgenic steroids in their bloodstreams by secreting their own endogenous hormones in response to the lengthening days.
Although steroids can improve performance in horses, steroid administration in itself does not assure enhanced performance. Generally speaking, horses are adequately big, strong, and fast enough. Steroid administration is not always a beneficial thing, especially over the long run. There are adverse reactions and side effects aplenty. When the dosage is excessive, or sometimes even with small dosages, difficult behavioral issues often arise. The biggest problem is that horses become hard to manage and handle. They act rank. With horses control is essential to safety and performance. It seemed Big Brown was plenty frisky as he broke out of the gate for the Belmont. Behaviorally and physically, there appeared to be little appearance of a lack of steroids in the big horse’s system.
Since steroids can indeed at times improve performance for some horses, they should be banned. There is little doubt that life will be healthier and safer for racehorses when steroid use is restricted. Artificially enhanced performance means that some medicated horses will exert themselves more than they might without steroids, putting added stress on their legs and muscles, leading to more injuries than would be the case without the added juice. Additionally, there are significant deleterious side effects due to the injudicious use of anabolic steroids: subsequent sterility, cancer, heart disease, unhandleabilty, psychological confusion, and other troubles.
Are there justified medical uses for anabolic steroids in racehorses? Yes, but justified medical use does not include enhancement of performance beyond what would normally be a horse’s inherent ability. What then are anabolic steroids used to appropriately treat? Anabolic steroids are given to help horses recover from certain medical conditions involving weight loss, reduced appetite, and loss of muscle mass. There are also valid medical uses for anabolic steroids to help horses recover more quickly and heal stronger after undergoing arduous surgical procedures, prolonged stress, and racing and training injuries. Anabolic (building up the protein) steroids induce metabolic protein retention, resulting in the incorporation of additional protein into the muscular and other structural tissues, bulking up the horses and athletes on the stuff.
Any other uses? Well, yes. Horses that are given significant amounts of catabolic steroids may need anabolic steroids to allay the protein loss the catabolic steroids induce. Catabolic steroids or cortisone (those steroids that break down protein and cause it to be excreted) are often administered to race horses to reduce joint, bone, tendon, ligament, and muscle inflammation, as well as to treat a plethora of other medical, immune, and metabolic conditions (pulmonary disease, hypoglycemia, tying-up, allergies, and many other medical issues).
Joints are injected with cortisone, and cortisone is also given systemically (intravenously, intramuscularly) to be absorbed into the bloodstream. Anabolic steroids compensate for the deleterious side effects of cortisone injections. If the use of catabolic steroids is limited, this will eliminate the medical indication to use anabolic steroids to compensate. If the industry is going to move forward in the best interests of race horses, they should significantly limit the use of cortisone as well. This will level out the drug-playing field, and bring our medical racehorse morals up to the standard of the rest of the civilized world.
Are there other examples of where one drug needs another follow-up drug to compensate for the side effects of the original drug? Yes. Phenylbutazone (bute), in addition to its vaunted non-steroidal, anti-inflammatory effect, thins the blood, increases the clotting time, and can increase the potential for bleeding into the lungs during racing (exercise-induced pulmonary hemorrhage, EIPH). If we ban the bute, the horses hopefully won’t bleed as much, and we can then reduce the need for Lasix.
Without bute and other NSAIDs in the horse’s system, the racehorse will be less likely to bleed. Both anabolic and catabolic steroids cause fluid retention, which also increases the possibilities to bleed with the increased blood volume. Lasix, a diuretic and lung-blood-pressure reducer, is used to eliminate this excess fluid.
The horse racing industry could begin to restrict the original allowed drugs bute and cortisone, thus reducing the need for Lasix, anabolic steroids, antibiotics (steroids impair immunity) and other drugs which tend to be needed to mitigate the side effects of the original drugs.
The preference of many is that race horses should run clean. Drug-free racing is safer. It favors sound horses. Fewer drugs, then, allow horses to race sounder and longer, and drug-free racing might protect the horseplayers a bit. If horses are treated with the drugs veterinarians determine they need to be treated with, then the patients should not be allowed to race until the resultant therapeutic drug levels have subsided to insignificant levels.
Will this no-drug policy then push trainers to use drugs that cannot be detected? Yes again, but then attempts to gain advantage with drugs have always been problematic in horseracing. Legalizing the use of bute and Lasix drugs did not curtail this activity, it simply enhanced it. Allowable drugs “clouded” the tests, hiding other drugs. Lasix diluted illicit drugs in the urine, making them harder to detect.
The 35-year-old raceday-drug horseracing experiment has failed, or is failing. Too many fractures. Too many wrecks. Too many injured jocks. Too many down, dead horses. It is time to start running American racehorses clean like horsemen do in the rest of the world. The cleaner, the better. Racing jurisdictions gave veterinarians and trainers the go-ahead to use drugs liberally in the 70s. And, as is apt to happen with drugs, some individuals abused the dosages and administration of those drugs. They topped allowable drugs off with more drugs, and in doing so did their horses and patients and the thoroughbred industry a significant disfavor.
The ethical rule of equine veterinary medicine is this: First, do no harm. When drugs are implicated with harm, then it is time to re-evaluate their use. The argument that legal drugs somehow help horse racing is getting weaker and weaker. Legal drugs engender the use of more drugs. Some drugs may have their place in racing horses, but we need more evidence to overcome the contradictory evidence that drug use is diminishing the public’s confidence in horseracing.
We’ll never forget those images of Eight Belles trying to rise on two broken legs. None of those who witnessed that misfortune will, not even Big Brown. But that image will fade and be less-likely to be repeated if we all get together to make racing a more reasonable sport for the horses’ sake, for everyone’s sake. It is a good feeling to win a horse race with a thoroughbred, but the ultimate good feeling in horseracing comes when a horse runs clean, wins, and returns to the barn fit and sound. Let’s get that feeling going, now.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
Belmont Stakes, 2008
June 8, 2008, 5:10 pm
Horse Racing Prevails
By SID GUSTAFSON
Big Brown burst from the gate fresh and fast. He immediately veered out, causing some concern that he was getting off the left front hoof (or was he just shying a bit from the starter in light of his freshness?). Despite his best efforts, Kent couldn’t contain his horse’s energy and settle him in. Checking can take the timing, balance, and rhythm out of a horse, disordering their physiology, expending their energy.
The heat, Brown’s rankness, the rough-going in tight company early, the necessity of having to rein heavily, the lost conditioning due to the quarter crack, the quarter crack itself, three races in five weeks, one mile and a half in the heat; all adequate reasons for the altered performance from the veterinary view. No surprises in the realm of equine medicine, at least.
The day was very hot; Brown was washing and foaming between the thighs. All the trouble the horse had to contend with early in the race expended needed energy not later available at the top of the homestretch. Down the backstretch Brown’s head was bobbing significantly more than the other racing horses, suggesting the onset of exhaustion.
Medically, the media and veterinary consensus thus far is that Big Brown is fine. Kent Desormeaux’s decision to pull the horse was commendable in light of the knowledge that a medical problem existed in his foot. No one wanted to risk the horse injury, especially his rider. The pressure was on to bring the horse home sound, and Kent did that. Big Brown expressed his displeasure at being held back, fighting with Kent, unfamiliar with having a herd of horses leave ahead of him, wanting to go on as Kent was bringing him to a stop in front of the grandstand. It appears our fallen hero was more likely exhausted than injured, for which we are all grateful.
Big Brown had a bad day, but things have could have turned out worse, as we all know. Horses humble men on a regular basis. Here is to the smooth and steady Da’ Tara, the sweet-riding Alan Garcia, and a superb conditioning job by Nick Zito.
The beauty of horse racing is overcoming great odds to win, rising out of the dust to prevail in the big race. The Da’ Tara team did just that, especially impressive in Saturday’s hot weather.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
Horse Racing Prevails
By SID GUSTAFSON
Big Brown burst from the gate fresh and fast. He immediately veered out, causing some concern that he was getting off the left front hoof (or was he just shying a bit from the starter in light of his freshness?). Despite his best efforts, Kent couldn’t contain his horse’s energy and settle him in. Checking can take the timing, balance, and rhythm out of a horse, disordering their physiology, expending their energy.
The heat, Brown’s rankness, the rough-going in tight company early, the necessity of having to rein heavily, the lost conditioning due to the quarter crack, the quarter crack itself, three races in five weeks, one mile and a half in the heat; all adequate reasons for the altered performance from the veterinary view. No surprises in the realm of equine medicine, at least.
The day was very hot; Brown was washing and foaming between the thighs. All the trouble the horse had to contend with early in the race expended needed energy not later available at the top of the homestretch. Down the backstretch Brown’s head was bobbing significantly more than the other racing horses, suggesting the onset of exhaustion.
Medically, the media and veterinary consensus thus far is that Big Brown is fine. Kent Desormeaux’s decision to pull the horse was commendable in light of the knowledge that a medical problem existed in his foot. No one wanted to risk the horse injury, especially his rider. The pressure was on to bring the horse home sound, and Kent did that. Big Brown expressed his displeasure at being held back, fighting with Kent, unfamiliar with having a herd of horses leave ahead of him, wanting to go on as Kent was bringing him to a stop in front of the grandstand. It appears our fallen hero was more likely exhausted than injured, for which we are all grateful.
Big Brown had a bad day, but things have could have turned out worse, as we all know. Horses humble men on a regular basis. Here is to the smooth and steady Da’ Tara, the sweet-riding Alan Garcia, and a superb conditioning job by Nick Zito.
The beauty of horse racing is overcoming great odds to win, rising out of the dust to prevail in the big race. The Da’ Tara team did just that, especially impressive in Saturday’s hot weather.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
Racehorse Heat
June 7, 2008, 7:45 am
It’s Hot Out Here for a Horse
By SID GUSTAFSON
Horses don’t like heat. They evolved in cool, even sub-arctic climates and are generally poorly-suited to deal with hot, humid weather. Heat makes horses sweat. Horses dissipate 75 percent of excess heat by sweating. The remainder of the heat is blown off by respiration. High humidity reduces the horse’s ability to dissipate heat by sweating, making it more difficult to keep the body temperature normal.
Hydration and electrolyte balance are critical in the racing thoroughbred. Muscle, nervous, pulmonary, cardiac, and joint function are vulnerable to electrolyte imbalances. Most electrolyte imbalances in thoroughbreds are caused by excessive pre-race anxiety and perspiration (washing out), which can be exacerbated by the use of race-day Lasix.
Potassium is one of the critical electrolytes depleted by washing out, as are sodium and chloride. Lasix depletes calcium and magnesium. These electrolytes are all essential for proper nerve, muscle, and circulatory function, and they all must be balanced in relation to one another.
When electrolyte dysfunction begins, wobbliness and weakness ensue, stressing the musculoskeletal system. After electrolyte imbalance becomes marked, the syndrome can move into thermoregulatory dysfunction, and the core temperature of the horse becomes elevated, causing further and more serious consequences. Although, high temperatures cause exercising horses to sweat heavily to dissipate the internal heat, susceptibility to heat stress is not solely influenced by ambient temperature alone. Excitable temperaments are the biggest culprit. Calm horses can generally maintain a normal body temperature and minimize sweating utilizing their ability to remain quiet and relaxed. In hot weather, anxiety-riddled horses can become electrolyte imbalanced before the race begins.
Other factors that may make horses vulnerable to heat include failure to be acclimated to hot temperatures and high humidity, tendency to sweat, and withdrawal of drinking water before racing. Racehorses may lose to 10-20L of sweat in a one-mile race. Fluid loss thickens the blood, making it flow more slowly, delivering less needed oxygen as the race perseveres. Additionally, hot horses redistribute blood flow to the skin in attempt to cool the blood off. This combination results in less blood being available for critical racing muscles, resulting in muscle weakness and cramping, weakness that may become especially noticeable in the last half mile of a one and a half mile race.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
It’s Hot Out Here for a Horse
By SID GUSTAFSON
Horses don’t like heat. They evolved in cool, even sub-arctic climates and are generally poorly-suited to deal with hot, humid weather. Heat makes horses sweat. Horses dissipate 75 percent of excess heat by sweating. The remainder of the heat is blown off by respiration. High humidity reduces the horse’s ability to dissipate heat by sweating, making it more difficult to keep the body temperature normal.
Hydration and electrolyte balance are critical in the racing thoroughbred. Muscle, nervous, pulmonary, cardiac, and joint function are vulnerable to electrolyte imbalances. Most electrolyte imbalances in thoroughbreds are caused by excessive pre-race anxiety and perspiration (washing out), which can be exacerbated by the use of race-day Lasix.
Potassium is one of the critical electrolytes depleted by washing out, as are sodium and chloride. Lasix depletes calcium and magnesium. These electrolytes are all essential for proper nerve, muscle, and circulatory function, and they all must be balanced in relation to one another.
When electrolyte dysfunction begins, wobbliness and weakness ensue, stressing the musculoskeletal system. After electrolyte imbalance becomes marked, the syndrome can move into thermoregulatory dysfunction, and the core temperature of the horse becomes elevated, causing further and more serious consequences. Although, high temperatures cause exercising horses to sweat heavily to dissipate the internal heat, susceptibility to heat stress is not solely influenced by ambient temperature alone. Excitable temperaments are the biggest culprit. Calm horses can generally maintain a normal body temperature and minimize sweating utilizing their ability to remain quiet and relaxed. In hot weather, anxiety-riddled horses can become electrolyte imbalanced before the race begins.
Other factors that may make horses vulnerable to heat include failure to be acclimated to hot temperatures and high humidity, tendency to sweat, and withdrawal of drinking water before racing. Racehorses may lose to 10-20L of sweat in a one-mile race. Fluid loss thickens the blood, making it flow more slowly, delivering less needed oxygen as the race perseveres. Additionally, hot horses redistribute blood flow to the skin in attempt to cool the blood off. This combination results in less blood being available for critical racing muscles, resulting in muscle weakness and cramping, weakness that may become especially noticeable in the last half mile of a one and a half mile race.
Sid Gustafson is a novelist, social commentator, and former thoroughbred attending and examining veterinarian licensed in New York, Washington, and Montana, where he has had significant experience in the regulation of racehorses, especially as it pertains to soundness and breakdowns.
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