Sunday, May 4, 2008

Eight Belles

First of all, I need to explain that while I am a veterinarian, I am no expert on race horses. During the first 17 years of my career, up until 1987, I worked on horses regularly, but never on a race horse. My only direct exposure to them was as a student at veterinary school 40 years ago.

Nevertheless, I have enough of an understanding of the situation to have some definite ideas about what went wrong, and why we see these horrific racehorse tragedies so frequently.

Horses, like all vertebrate animals, have physeal plates – growth plates – in their bones. While the horse's bones are growing, those growth plates are composed of cartilage, and thus represent weak spots in the bone. Once the horse's bones have reached their maximum length, those growth plates ossify, or turn into solid bone. From then on, the growth plate area is just as strong as the surrounding bone.

Horses' bones continue to grow, although at a decreased rate, until the horse is nearly 5 years old. Yet, we race these horses competitively as 2-year-olds, and begin to train them intensively months earlier. Why, then, should we be surprised when some of these horses break their legs in such spectacular fashion?

Keep in mind, too, that by tradition, the Thoroughbred industry clings to a quaint custom for calculating the age of racehorses. Regardless of when in a given year a horse is born, its birthday is considered to be January 1st of that year. Most foals are dropped between February and May, so a so-called "yearling" on January 1st of the following year may well be only 8 months old in real time.

In truth, the problem is far more severe than most racing fans know. The industry's deep, dark secret is that they are racing these colts and fillies much too young. Everyone involved knows it, yet they never say it publicly.

Once in a great while, someone publishes an article laying out the unvarnished truth about this uncomfortable subject. One such appeared in the British scientific press about 15 years ago, "Early casualties of a sporting life: Thoroughbred racehorses are pampered aristocrats of the equine world. But many have their careers cut short by injuries that some say are caused by pushing them too hard too soon" by John Bonner (New Scientist, 20 March 1993).

Let's look at a few choice quotes:

Lameness is the single biggest factor preventing young racehorses from running. Some vets argue that injuries to leg bones and tendons are the result of pushing animals too hard and too soon – before they are physically mature. The racing industry accepts that pitting two-year-olds against one another is risky, but regards it as economically essential, especially when racing is in the grip of recession.

A bit later,

Horses have a natural lifespan of more than 20 years and do not stop growing until they are around five. In a two-year-old horse new bone is still being laid down in the epiphyses or growth plates near the ends of the bones. New bone is made up of cartilage-like material which gradually hardens as it is permeated by calcium and phosphorus. In the bones of the leg, these growth areas have to support the animal's weight and their softness makes them particularly vulnerable to injury.

Once in a while, experts speak frankly:

Some vets argue that two years is too young an age to race horses. They maintain that the rigours of training contribute to lameness. 'I would say that they are raced too early and too fast,' says Alastair Mews, assistant chief veterinary officer with the RSPCA.

Brian Singleton, the former director of the Animal Health Trust, Britain's leading equine research centre, says: 'The epiphyseal growth plates are still open in the leg bones of a two-year-old horse. They are beginning to close in a three-year-old. Inevitably, these structures can be damaged by the stresses of training and racing. I strongly feel that two-year-old horses are just too young.'

Why the rush to race these horses before they're ready? Money, of course:

Racing exists for betting and the industry is dependent on the money betting generates. A horse has to show its speed and stamina in races restricted to two-year-olds to develop the form that will encourage punters to spend their money on classic races, such as the Derby, when they are three. To stop racing two-year-olds would force a complete overhaul of this system.

Then, this frank admission:

The cost of training an animal is at least £150 a week, and few trainers could afford to keep a horse off the racetrack for an extra year. According to Deborah Baker, president of the British Equine Veterinary Association, if two-year-old racing were curtailed, the industry would crumble.

To get a good, fair, balanced view of the entire situation as it exists in the British racing industry, read the whole thing. As far as I know, the problems and concerns of the US industry are similar, although the industry is, of course, much larger.

If you're not familiar with the physical arrangement of growth plates within bones, here is a diagram and a couple of x-rays to help you understand. All three involve the human knee, a joint which is easy for most of us to understand, since so many of us have had problems with our knees at one time or another, or have close family members who have. Therefore, we have probably seen knee x-rays before.

The diagram shows the locations of the growth plates in the bones of the human knee. Then, there are x-rays of a normal right knee and a severely injured left knee.

Here's the normal right knee.

The left knee has suffered a particularly nasty growth plate fracture classified as a "Salter-Harris Type IV." I've made a few notes on the picture to help you understand what you're seeing. The exact meaning of the classification system is not important. Suffice it to say that this type of fracture is a challenge to the skill of the finest orthopedic surgeons, and can never be expected to be completely normal regardless of the procedure used to repair it. The reason is that such a severe injury to an active growth plate can be expected to result in premature physeal closure – the cessation of growth before the bone has reached its full length.

In humans, premature physeal closure can result in one limb being considerably shorter than the other, or even in curvature of a limb if the injury occurs to either the forearm or the shin. Such cases require further corrective surgery, such as Ilizarov limb-lengthening procedures or wedge osteotomies and compression plating to straighten crooked limbs. If you're interested in knowing more about growth plate injuries in humans, here's an excellent reference from the National Institutes of Health: "Q&A: Growth Plate Injuries"

Many of these procedures are equally applicable to dogs and cats. The cost may be an insurmountable obstacle for many owners, but the procedures are not only technically feasible, but are now performed almost routinely in veterinary teaching hospitals and specialty surgery practices.

Horses, though, are a different matter. People who have never worked with them invariably don't understand, but the fact is that even in cases where the horse's owner is willing and able to pay the bill, and states plainly that money is no object, it is often impossible to save these horses. Those who may doubt that hard reality got a sad lesson 2 years ago in the case of Barbaro.

In that case, the horse broke only one of his hind legs. In addition, the skin was not torn open – thus, there was no bacterial contamination of the wound. Nevertheless, despite the great skill of the attending veterinarian and the determination of all involved to see the case through to a successful conclusion, we all know what happened.

Because of the additional stress placed upon it, the opposing, uninjured limb broke down and developed laminitis – founder. Some of the finest equine veterinarians in the profession tried their best to stop the process, but it inexorably progressed to the point where the tip of Barbaro's 3rd phalanx, the coffin bone, broke through the sole of his hoof. That in itself would have been a devastating complication, but when coupled with the condition of the opposing limb – fractured, repaired, and healing nicely, but still far from normal – his case rapidly became hopeless. At that point, the owners had to make the sad decision to authorize Barbaro's euthanasia.

Eight Belles never had a chance. Not only did she simultaneously break both of her forelimbs, but at the time of the injury, the bone came through the skin of the left leg, thus turning an already grave situation into a compound fracture. Thus, she had two insurmountable problems. First, she did not have one good limb to support her weight during a protracted healing period. Second, she had a contaminated lower leg wound – a bad enough situation in dogs and humans, but devastating in horses, which, despite their great strength, have far less innate infection-fighting ability than humans, small animals, or even cattle.

No doubt, those unfamiliar with horses will be second-guessing the decision to euthanize Eight Belles for some time to come. In my opinion, though, there is no question that they did the right thing.

While we can never prevent every accident, we can easily prevent the vast majority of these gallant young racehorses from experiencing the sort of violent, agonizing end that we have now seen twice within two years. Just as we no longer permit child labor in this country, we should no longer tolerate the spectacle of immature horses racing their hearts out for our amusement, and putting their very lives in peril in the process.

UPDATE: We might have known this was coming – PETA has weighed in: "PETA wants Eight Belles jockey suspended after filly's death". As usual, they've got it wrong. This tragedy was not the jockey's fault. He was just doing his job. The only aspect of PETA's faxed letter that makes any sense is their demand for limits on the age of racehorses. In that respect, and only in that respect, PETA and I agree. Otherwise, in my opinion, their fax was a waste of valuable fax paper.

4/20/09 NOTE: If you came here to read about Eight Belles, you'll also want to learn about the latest outrage, the unfolding tale of an Equine Massacre.


  1. This is cool, my sister will especially love your blog. She is horse mad - and used to want to be a vet. :-)


  2. Very interesting read Doc. I've always felt racing is just a money pit for horse owners, not flesh and blood. In terms of horse years vs. human years, keeping in mind horses live 20 yrs or so, and humans live to 75 or so, would you put your 10 yr old son or daughter in a race like this? Not me. Thanks for introducing me to your blog.