The charts presented here contain data of interest to all Thoroughbred breeders. They compare all Triple Crown winners plus other great American racehorses selected to give a fairly even representation through time. Popular sire lines are marked. Note the pattern of dots at the bottom, which represent sire-line or damsire-line ancestors that appear only once in a given pedigree (“non-repeats”), an excellent measure of the individual animal’s heterozygosity and allelic diversity.
SIRE LINES: In earlier years, the St. Simon–Vedette bloodline (black) was the most popular, with Nashua having seven repeats in his pedigree. Old Eclipse bloodlines, especially Bonnie Scotland (green) were also heavily patronized. The Phalaris era (pink line) begins with Native Dancer in 1953, accelerates with Northern Dancer (1964), and then comes into absolute dominance after Secretariat (1973). In round numbers, the average number of non-repeated sire-line ancestors for the whole time period is four. It is five before 1975 but falls to three for the period 1975 to 2018. Horses with the highest sire-line diversity are War Admiral, Citation and Carry Back with seven and, outstandingly, Secretariat with nine. In stark contrast, 13 of Justify’s 16 sire-line ancestors trace to Phalaris, with three non-repeats.
DAMSIRE LINES: The trend in damsire lines lags behind that of sire lines, but Phalaris creep is nonetheless evident: Early Vedette and Bonnie Scotland (green) lines drop off as the pink Phalaris line rises. The pattern of non-repeats is a little different than for sire lines: The overall average is three, but for early years it’s only 2.5. After 1975, it rises to 3.5, indicating that as diversity in sire lines fell, Thoroughbred breeders have in fact sought broodmares with a broader genetic base.
Ten of Justify’s 16 damsire-line ancestors trace to Phalaris; in total 23 of 32 ancestors represented in Justify’s five-generation pedigree trace to this one animal, yielding an inbreeding coefficient of over 70 percent, far higher than the Thoroughbred average of 12.5 percent. He has four non-repeated damsire-line ancestors. In contrast, horses with the highest damsire-line diversity are Pleasant Colony with six and Assault, Middleground, Tim Tam, Kauai King and Hansel each with five. If pursued, a strategy of seeking broodmares with more diverse pedigrees will shore up the long-term viability of the breed.
Secretariat’s pedigree. Cunningham and colleagues frankly state, “The Thoroughbred horse breeding industry has changed dramatically in the last 40 years with the current emphasis [on] production of yearlings to fetch as much money as possible at auction, rather than the previous goal of producing superior racehorses.” They go on to say, “This commercial pressure has resulted in a decrease in the number of stallions in the breeding population and a large increase in the number of foals sired by popular stallions. Forty years ago most stallions covered a maximum of 40 mares per season, compared with [some] current stallions that cover close to 200 mares. The ‘big book’ era [really takes off] with the foal crop of 1996. These changes lower the effective population size of the breed” ---and the inevitable result is a steep increase in inbreeding.
HISTORICAL TENDENCY TO INBREEDING
The founding of a breed, which by definition involves the inclusion of some individuals while excluding others, is itself a “genetic bottleneck” that reduces the diversity of alleles. Alleles are clusters of molecules associated with different functional zones (loci), along the DNA strand. Variant alleles govern the same aspects of the individual’s growth and physiology but accomplish the task in slightly different ways---for example, by favoring some metabolic pathways over others or by increasing (or inhibiting) the production of certain proteins, enzymes, amino acids or cell types. These basic chemical and physiological functions underpin every aspect of life, including growth, development, reproductive success, immunity to disease, the ability to heal from injuries, overall
soundness and athletic performance. Allelic diversity within an individual’s genome is a measure of its degree of heterozygosity0. Cunningham and colleagues found that Thoroughbreds possess 37 percent fewer alleles than other horse breeds studied.
A small number of founder individuals, genetic drift (the statistical tendency for homozygosity0 to increase in isolated populations) and the disproportionate use of popular sires are important factors acting to increase inbreeding in domestic mammals. Historically, old breeds with closed studbooks also tend to have high rates of homozygosity and low allelic diversity. To understand recent breeding trends in the Thoroughbred, it’s important to realize that for all of the above reasons, the breed was already at high risk for allelic loss even before the current fad for Phalaris.
The Thoroughbred was created in the 17th century with a relatively small
population of less than 400 individuals, and the studbook was effectively closed by 1791. After its founding, the breed went through several additional bottlenecks. While other stallions were responsible for paternal lineages early in its history, by the mid-1800s only three remained: the Byerley Turkmene, the Darley Arabo-Turkmene and the Godolphin (called an “Arabian” but actually an almost even mix of Turkmene, Hobby and Barb; see “A Brief History of the Thoroughbred,” EQUUS 448). Further, each of these three foundation sires is linked to the living population through only one male-line descendant: Herod (Byerley Turkmene), Eclipse (Darley) and Matchem (Godolphin) (see “Foundation Sires and Dams,” EQUUS 449).
The percentage of paternal lineages attributable to the Darley has been increasing for more than 175 years and is now responsible for 95 percent of paternal lineages in the modern population
(see “Eclipse on Top,” EQUUS 451). Indeed, Cunningham’s survey found that just 10 foundational Thoroughbreds were responsible for 45 percent of the genetic makeup of the sample of living horses studied. The top 20 contributed 65 percent and the top 30, 72 percent. The contribution of all 158 identified founders equals 81 percent, with the remaining 19 percent due to unknown factors, including novel mutations and unrecorded or undocumented ancestors.
The most important Thoroughbred ancestor is the Godolphin, responsible for 13.8 percent of alleles in the living population. He is followed by the Darley with 6.5 percent, the Curwen Bay Barb at 4.2 percent, the Ruby mare at 4.2 percent and the Byerley Turk at 3.3 percent. The distaff side of the pedigree is important because mammals inherit all somatic cellular functions (which are governed by the “extra-nuclear” or “mitochondrial” DNA) from their mothers. According to Cunningham’s study, just 10 foundational broodmares account for 72 percent of maternal lineages. The top 20 are responsible for 89.9 percent of the maternal lineages in living Thoroughbreds, while the top 30 account for 94 percent. These findings are in accord with studies of wild mammal populations, which have shown that the effective number of founders becomes constant after only a few generations; in other words, some animals leave disproportionately large numbers of offspring while, over time, the contributions of others simply wash out. The genetic contribution of favored foundational individuals then tends to wield constant influence through all future generations.
Market-based selective breeding, which for the modern American Thoroughbred means seeking to produce yearlings that will sell at auction for the highest prices, increases potential for the disproportionate representation of popular sires. When a population goes through a bottleneck, rare alleles tend to be lost as allelic diversity is reduced, but Cristina Luis, PhD, E. Gus Cothran, PhD, and Maria do Mar Oom, PhD, writing in the Journal of Heredity in 2007, make the significant point that the heterozygosity (inbreeding coefficient) calculated for the whole population is not reduced proportionally, because rare alleles contribute little to heterozygosity. Rare alleles lie at the root of superior physiology, and anyone who hopes to produce a great racehorse should be in quest of them, for rare alleles and rare combinations of alleles are the genetic key to the outstanding athleticism shown by Man o’ War and Secretariat.
The chance of putting rare alleles into play increases as the number of different ancestors increases. Compare the high diversity of ancestors represented in the pedigrees of champions such as War Admiral, Citation, Tim Tam, Carry Back, Kauai King and especially Secretariat versus the muchtouted and heavily Phalaris-bred Northern Dancer, Seattle Slew, Swale, Sunday Silence, Hansel, War Emblem, Smarty Jones, I’ll Have Another, American Pharoah and Justify!
DELETERIOUS EFFECTS OF INBREEDING
Common wisdom among animal breeders encourages “breeding the best to the best to get the best.” Breeding winners to winners is supposed to be the best guarantee of producing a winner---but in terms of genetics, this protocol promotes an increase in the degree of homozygosity, which means a decrease in the diversity of alleles within the individual’s genome. When different alleles interact with each other, as well as with alleles at other nearby loci, the effect is called pleiotropism. Pleiotropisms are often advantageous, and they confer what is termed “hybrid vigor.” In physiological terms this may mean greater size and strength, increased resistance to disease, increased metabolic efficiency, increased soundness, or increased fertility through greater semen quality and higher conception and foaling rates. It can certainly also mean greater potential for speed, and that’s the bottom line in breeding racehorses. Unfortunately, while homozygosity may increase a racehorse’s speed and thus his chances of winning, the same homozygosity at other loci acts to inhibit other---and often more subtle---advantages conferred by hybrid vigor.
Most variant alleles have neutral to positive effects, but some are deleterious or even lethal. Most deleterious effects are not strong, creating only slight depressions in physiological functions, soundness or fecundity (conception and foaling rates), but others cause or contribute to what is broadly termed “genetic disease” or inheritable disease. Heterozygous individuals with greater allelic diversity have markedly lower levels of genetic disease, whereas the chance of genetic disease and the potential to pass genetic diseases to offspring increase with homozygosity.
Inbreeding is defined as the probability that any given pair of alleles in a foal are identical---one inherited from its sire and an identical one from its dam. The inbreeding coefficient is calculated by tracing the pedigree of an individual back to common ancestors. This leads us to an understanding of why inbreeding is of such concern: Hundreds of studies conducted over the past century on many different species of mammals demonstrate “inbreeding depression”---reduction in fitness, the ability to adapt, survive and thrive---in wild populations with high degrees of inbreeding. Likewise, Cunningham’s
team notes that “while some studies have not found significant effects of inbreeding on reproductive fitness in horses … there is continuing concern that the narrowed genetic base of the Thoroughbred may be limiting progress in performance and contributing to an increased frequency of heritable diseases.” Certainly, Phalarisintense pedigrees have not worked to increase racing speed---race times in Triple Crown contests are not even close to records set by Secretariat more than 40 years ago---even considering Justify’s standout performance in this year’s Preakness Stakes.
Decrease in fecundity is thought to result from an increasing proportion of embryos that are homozygous for lethal recessive alleles. Such foals typically die in utero and are either silently resorbed or else recorded as aborted pregnancies. Modern practices, such as the use of hormones to induce estrus and ovulation and to improve reproductive rates, can mask negative effects of inbreeding, but deleterious effects of homozygosity can still be detected.
For example, in studies involving more than 2,000 English and Irish mares L.H. Morris, W.R. Allen and colleagues writing in the Equine Veterinary Journal report high levels of embryo loss: While 94.8 percent of Thoroughbred mares were reported pregnant at some point in the breeding season, the foaling rate was only 82.7 percent. In parallel fashion, a report in the Journal of Animal Science by M. Sevinga and colleagues in the Netherlands found that a high incidence of retained placenta in Friesian horses is significantly correlated with degree of inbreeding. The inbreeding coefficient in the modern Friesian is even higher than in the Thoroughbred, ranging from about 15 percent to 19 percent.
Deleterious effects on conformation and soundness attributable to high degrees of inbreeding have also been reported for a dozen horse breeds, so it should not be surprising that these effects, including reduction in height, heartgirth, cannon bone circumference, hoof size and horn quality would show up in the Thoroughbred as well, even though it is difficult to establish a direct causative link between inbreeding and such catastrophic structural breakdowns as those suffered by Eight Belles, who sustained multiple fractures after finishing second in the 2008 Kentucky Derby, and Barbaro, who won the 2006 Kentucky Derby but broke his leg two weeks later in the Preakness Stakes.
While these disasters raised public concern because they occurred during Triple Crown races and were broadcast on TV, they are but the tip of the iceberg. A good indication of diminished soundness in the Thoroughbred horse was reported by E. Mitchell in 2008, who showed that the average number of career starts in modern flat-track racers is much less than it was 40 years ago, suggesting that the majority of
horses bred for the track might not be able to endure more than the halfdozen starts that is the average today. Forty years ago, the average was more than 50 career starts for elite-class horses, with some individuals logging 150 starts before retiring to stud (see “The Thoroughbred Gene Pool,” EQUUS 452).
CONFORMATION AND GROWTH
The modern trend toward intense Phalaris breeding presents a unique opportunity for researchers to examine large numbers of horses who are more closely related than half-siblings. Of extreme value to breeders would be conformation analysis of a “statistical” sample of Phalaris-breds (i.e., 50 or more individuals). Results are more certain and trends more valid as the number of horses studied grows. Lack of space here restricts me to merely showing breeders how to set up such a study.
Since I can feature only a few individuals, I have chosen to begin with those most closely related, i.e., horses tracing in either sire line or damsire line to Phalaris through the popular stallion Mr. Prospector. The first question of interest is whether there is a family resemblance; I address this both by direct comparison of the related horses and by contrasting them with horses of different breeding. Analysis reveals that Phalaris-breds do in fact look similar, with generally small differences in body proportions. At the same time they look different from champion-quality Thoroughbreds of other breeding.
Horses bred from Mr. Prospector go back through Phalaris to Bend Or, and thence through Birdcatcher and Pot8- O’s to Eclipse. Eclipse-bred horses
all have a tendency for lower withers, thicker muscling, a more “downhill” build, and a more “rounded” look to the neck and haunches compared to Thoroughbreds who descend from either Matchem or Herod. Their get are by contrast generally taller, with
higher withers, more level overall body balance, a long “slashing” shoulder, and flat, lathy musculature. Almost all Matchem-line horses in our day descend from West Australian, and many of those (especially in America) come from his descendant Man o’ War. They tend to be longer-bodied than Eclipse-breds, with massive bone. The Phalaris-breds featured in this article consistently present the rounded Eclipse body style, with the most divergent individual being Bravazo, the only sire line Phalaris horse in this study whose damsire line goes to Matchem (through Man o’ War) rather than Eclipse.
Many available photographs make it possible to look at Phalaris-breds at different times in their lives. Another study that would give important results useful to Thoroughbred breeders and trainers would track the pattern of growth and maturation among these closely related horses and contrast that with elite-class racehorses of other bloodlines. I have not attempted that here because the focus of this article is to look at Justify’s conformation and performance as a 3 year old. However, even though my sample is not big enough to constitute statistical significance, it is of interest to see how Justify’s appearance and structural frame change from the time when his race training began at the age of about 2 years to his 3-year-old photo taken just before the 2018 Belmont Stakes. Likewise, photos of American Pharoah are now available at ages 2, 3 and 6.
INBREEDING AND CONFORMATION
Does inbreeding create horses that are conformationally inferior or structurally weak? After the Eight Belles and Barbaro disasters this possibility came into wide discussion. For horse breeds, as with dog breeds, this question must be answered in terms of numbers and time. Numbers, because unless the foal dies in utero, with modern veterinary care and ordinary good luck, it will probably live to adulthood. All
Phalaris-bred foals are not of stakesclass quality any more than are all foals of any other breeding; and historically in the Thoroughbred there has always been an enormous amount of pruning ---or wastage. Only a small percentage of superior individuals make the grade as racehorses, while those who don’t will be euthanatized or gelded and sold to horse-show competitors or backyard owners. The majority of them are perfectly viable individuals who get along just fine under less intense athletic demand.
It is important to keep this in perspective because every horse presented in this article is of championship quality. Even top-class Phalaris-breds, however, show conformational differences both on the plus and on the minus side when compared to horses of other breeding. On the plus side, they tend to have near-level overall body balance, just “downhill” enough to prevent “flying up” and wind resistance with acceleration. They also have long forelimbs, which helps them reach forward to increase the length of stride. An important but more intangible factor is that they tend to be good-minded and easy to train. On the minus side, two functionally significant problems plague them: first, diminishing “bone”---limb circumference diminishing from the knee downward to the hoof, particularly with a tendency toward small, round ankles backed by small sesamoids. The second problem has been shelly, thin hoof horn and/or thin soles and digital cushions. Like the Quarter Horses they resemble, Phalaris-breds are massively muscular but tend to have less than the ideal amount of “bone” to support the weight of the body above and, particularly, to withstand without breakdown the thrust, torque and impact forces that their powerful musculature
generates (see “A Sense of Proportion,” EQUUS 388).
Again as in the Quarter Horse, Phalaris-breds are disadvantaged by the fact that they appear to mature early. I say “appear” because there are no early maturing horses in terms of skeletal development; all horses’ bones mature at the same rate, and no horse on Earth is skeletally or dentally mature until he is 6 years old. Races for 3-year-olds such as the Kentucky Derby, Preakness Stakes and Belmont Stakes are open only to horses who have not
yet achieved skeletal maturity. Horses who appear more mature on the outside than their skeletons within can “fool” a trainer into pushing them too hard. This is an area where I think Bob Baffert has shown both knowledge and wisdom, because all his colts appear to love to run ---implying that they have been “exposed but not over-exposed,” in other words, they have been properly conditioned but have not experienced significant pain from excessive athletic demand. Justify, however, also stands out over all his closely related
competitors in possessing very correct, substantial limbs, powerful hindquarters and harmonious build. Of all the horses reviewed here, Justify’s conformation is the most similar to Secretariat’s (and so is his running
style, which we will discuss later).
Above, I also mentioned the factor of time. How long---how many generations---of inbreeding can a population of horses stand before the percentage of viable athletes drops below a level that is economically or functionally sustainable? At what point does genetic “load”---the burden of deleterious alleles packed into the genotype0 by inbreeding ---become so great that few if any foals grow up to actually race? Some wild populations of other species, such as the cheetah and snow leopard---which historically have suffered from severe population loss and bottlenecking and thus have inbreeding coefficients far above those of Thoroughbreds---continue to produce viable offspring albeit with alarmingly low conception and birth rates. Genetic diseases associated with inbreeding that would obviate a racing career include hydrocephalus, congenital blindness and wobbler syndrome, which are present and increasing in the Thoroughbred.
In a significant 2009 study, Robert C. Tyron and colleagues tested 1,031 American Quarter Horses and American Paints for five deleterious alleles: HYPP (hyperkalaemic periodic paralysis), LWFS (lethal white foal syndrome), GBED (glycogen branching enzyme deficiency), HERDA (hereditary equine regional dermal asthenia), and PSSM (type 1 polysaccharide storage myopathy). All horses tested were performance champions in an array of disciplines including barrel racing, cutting, reining, Western pleasure, halter, working cow and racing. Halter horses had significantly greater frequencies for HYPP and PSSM (more than 200 times higher) than other groups---probably because the hypermuscular phenotype0 that wins Quarter Horse and Paint Horse halter championships is enhanced by HYPP and/or PSSM. By contrast, racehorses had the lowest frequencies. “It is unclear why the racing subgroups had a lower frequency of disease alleles,” the researchers noted, “particularly because heterozygous carriers of autosomal
recessive conditions do not presumably have a phenotype associated with them. Less intensive inbreeding … coupled with the use of various sire lines … may have limited the amplification of [deleterious] allele frequencies in racing bloodlines. Thoroughbreds continue to be bred into the American Quarter Horse lineage through the use of appendix Quarter Horses.”
How do economics play into increasing inbreeding? A horse race is won by the fastest horse that shows up on race day, not necessarily by an exceptionally fast horse. Is betting on a race between snails or turtles just as entertaining as betting on a race between horses? Since the report by Cunningham and colleagues in 1991, 10-year averages for winning times, even for races of one mile or less, no longer appear to be dropping, and race times for Triple Crown winners are certainly slower than the records set in 1973 by Secretariat. As long as the rules for Thoroughbred racing mandate no minimum qualifying speed---expressed in seconds per mile or miles per hour (as in harness racing)--the potential for short-term profitability will almost certainly prevail over any concern for the long-term soundness or overall viability of the Thoroughbred.
The modern trend in Thoroughbred breeding for producing marketable yearlings rather than creating great racehorses is surely both silly and unsustainable in an athletic discipline where both speed and soundness are required. Justify will certainly retire to stud, and assuming he proves to be fertile, he will pass on his intense Phalaris heritage to every foal he sires. Every time he is bred to a Phalaris mare, the degree of inbreeding doubles again. Is it no longer possible to bring mares of other bloodlines to a champion like Justify? Are such mares no longer available? I would love to see Justify cover a book of mares heavy on Dark Ronald (Touchstone–Sir Peter Teazle/Herod), Princequillo (St. Simon–Birdcatcher), Hyperion (Bay Ronald/Touchstone–St. Simon/Vedette), Tetrarch, Man o’ War or West Australian breeding. Such mares are still commonly used to produce champion eventers, timber racers, steeplechasers and jumpers who are not only sound but fast. Fast racehorses have not come exclusively from Phalaris breeding, either recently or in the past.
On this basis, we obviously also want to know whether there is a Phalarisbred galloping style that is faster than that of other bloodlines. The review above makes it clear that it doesn’t matter whether the winning horse is fast, as long as he can outpace others against which he is raced. When high-stakes racing is essentially a clone war with every horse closely related to his competitors, galloping efficiency may make the difference between championship and obscurity.
I have previously reviewed gallop biomechanics of fast horses and of other mammals such as cheetahs that are also fast runners versus slower species such as giraffes or elephants. I am amused, and perhaps not too surprised, to see my illustrations and text reproduced (without attribution or credit) in several online Thoroughbred blogs. What my reviews have apparently accomplished---especially “Secrets of Secretariat’s Speed” (EQUUS 434)---is
to make Thoroughbred fanciers aware that there is such a thing as a doublesuspension transverse gallop---and that horses capable of it are inevitably winners. A few champions across bloodlines, including Man o’ War, Phar Lap, Seabiscuit, Princequillo, John Henry and Secretariat, consistently showed this galloping style, and Justify also appears to belong to this elite cadre. A horse’s ability to produce this type of gallop depends upon neuromuscular coordination and the elasticity of his back as much as upon superior power. No
study of the prevalence of the doublesuspension transverse gallop has been performed to date upon a statistical sample of Thoroughbreds, but it would be relatively easy to do and would yield enormous practical benefit to flat-track trainers as well as to investors who select which colts to purchase for training.
A telling comparison I have not presented before analyzes galloping style in terms of thrust and landing phase. The premise is simple: If the center fielder in a baseball game catches the ball and the play is at second, he will
throw the ball in a low arc directly to the second baseman. If, however, the play is at the home plate, in order to hit the catcher’s mitt the center fielder will have to throw the ball not only with more power, but with a much higher arc. In short, the potential flight distance is a function of the height of the arc. This is a major insight when it comes to speed in racehorses because the fastest horses are those who spend the most time flying through the air during the gallop’s period(s) of suspension. In this comparison, Secretariat
shows himself to be essentially unbeatable. However, Justify’s technique is very good, and I am especially impressed by his elastic back and long forelimbs, which allow him to stretch far forward during the landing phase.
Yet another way to assess championship speed in racehorses is to look at the pelvic angle in the most collected versus the most extended phase of the gallop. Racing speed, as I have pointed out in many previous articles, is not primarily created by the horse’s legs. Rather, it is the flexibility of the animal’s back, particularly the coiling and uncoiling of the loins, which is the biomechanical heart of speed. Coiling of the loins is effected by the horse’s abdominal and iliopsoas musculature, while uncoiling is accomplished by the perivertebral muscles---primarily the
longissimus dorsi---which parallel the spine and extend from the base of the neck to the pelvis. To create forward thrust, the horse first coils his loins. Then he presses one or both hind limbs against the ground as effort switches from the abdominals to the long
perivertebrals. The body is thrust forward as the longissimus dorsi contracts, uncoiling the loins. The more deeply the horse coils its loins during the collected phase of the gallop, the greater the range through which it will uncoil them during the
extended phase, and this is what creates superior speed.
Justify comes off the winner in this comparison---even over Secretariat! Justify’s maximum loin-coiling rolls the rear end of his pelvis down some 37.4 degrees, more than Secretariat’s
maximum at 34.8 degrees. The best photo of Secretariat’s uncoiled pelvis reveals an angle of 19.5 degrees---this is the most his pelvis and topline “flatten out”---whereas the remarkable photo of Justify that I analyze here catches him in the same phase of the gallop stride with pelvis uncoiled to 3.8 degrees, creating a difference of 33.6 degrees between coiled and uncoiled phases, much more than what available photos allow me to document for Secretariat. Man o’ War shows a difference of 26.8 degrees and American Pharoah shows 16.3 degrees, both of which are also greater than Secretariat’s 15.3 degrees.
Conformationally, Secretariat’s pelvic angle is not only longer but steeper than either of the Phalaris-breds or Man o’ War. A steeply-angled pelvis conduces to power but not flexibility, as it is more difficult for such a horse to “uncoil” the loins. Nonetheless, Secretariat is the fastest of the four horses analyzed, and this tells us exactly what would be needed to create a champion that could run faster than Secretariat: the same spinal elasticity shown by Man o’ War or Justify, combined with a longer, somewhat steeper pelvis packing greater power.
Straight carriage is another factor crucially important to racing success. A train whose wheels are partly off the track, or a car that needs a front-end alignment not only wastes fuel but
This is a major insight where it comes to speed in racehorses because the fastest horses are those that spend the most time flying through the air during the gallop’s period(s) of suspension.
operates as if driven forward with the brakes on. A horse who runs crooked--with his body out of alignment with his intended direction---will not only be slower than he should be, but will prematurely wear his joints out.
Horses with crooked carriage show a pattern of overweighting either the left or the right pair of limbs, and they pound especially heavily upon the fore hoof of the favored side. My review of films of American Pharoah brought out the fact that he often ran with his head angled off to the right, implying that he overweights the left pair of limbs and especially the left forelimb (see “American
Pharoah and the Triple Crown,” EQUUS 458). Another story in the same issue, “American Pharoah’s Lucky Horseshoe” describes the special “Pharoah plate” that the colt needed to wear on his left fore hoof. I was of course sorry to see this confirmation of crooked carriage in a champion.
American Pharoah proved to be generally a bit above average in terms of race times; how fast would he have been had he been taught to run straight rather than merely specially shod in order to try to make up for the fact that he ran crookedly? The knowledge of how to help a horse discover straight carriage has not been common at the flat track (or, in all fairness, in any other equestrian discipline), but the techniques have been known for more than 300 years. I have said in print that I believe Secretariat, who showed remarkably straight carriage, taught this efficient (and more comfortable) way of going to himself. Justify likewise runs straight and handles the turns fluidly, in a manner comparable to Secretariat.
I’ve presented a lot of data in this review, with suggestions for needed research that could easily be funded by the industry. The bottom line of this discussion goes directly against the short-term-gains philosophy that says “winning is everything, and only winners count.” What I’m suggesting is that to create great racehorses, breeders must turn to “good” individuals---fast, sound, correctly conformed and goodminded---who did not happen to win. In short, to get great racehorses, and (more important) to preserve the future viability of the Thoroughbred, it is vitally necessary to breed to losers! It will also be necessary for more trainers to take certain pages from other equestrian
disciplines in terms of selecting appropriate colts and fillies, conditioning them and teaching them to understand and love the game they’re being asked to play.
The Thoroughbred is the world’s greatest breed of horse, but its future is in jeopardy. With enlightened practices in both breeding and training, we can look forward to a continuing string of Triple Crown champions who are not just designer-bred one-note Johnnies but who, like Justify, exemplify the superior athleticism that is the Thoroughbred’s birthright.