September 24, 2011


Why does a broken leg mean the end for a horse?: Senior vets explain why it is often impossible to save an animal after an injury that would hardly ever threaten a human's life (Chris Cook, 23 September 2011, The Guardian)

In search of explanations, I pitched my naive questions to two well-respected vets at the British Horseracing Authority. Professor Tim Morris is their director of equine science and welfare while Jenny Hall is a vet based in Lambourn who will be veterinary services manager at the Olympics next year. I'm very grateful for their time and patience.

1) Most humans recover easily from broken legs. Why can't horses?

"The problem is, because their bones have become lighter," Hall told me. "They're very strong, to carry their weight, yet they're light, for them to be able to go fast. So, unfortunately, sometimes, when they break, they just shatter."

When that happens, it is not possible to repair the bone, and not just because it is now in lots of little pieces that won't heal together. Another issue is what Hall called "plastic deformation", meaning that the bone bends before it breaks and it is the bent shape that is preserved in the pieces. Even if it were possible to put the pieces back together, you would end up with a madly bent bone.

Hall continued: "When you look at their lower limbs, which is where a high incidence of these injuries are, there's very little soft tissue covering the bone. So unfortunately, often, if there's a fracture, it may well be that the bone penetrates the skin, which turns it into an open fracture.

"Even in people, that makes it a much harder situation to get good healing. So you can imagine, with a horse, no matter how quickly a jockey pulls it up, it's hard for the skin not to get damaged and also for the blood supply to get damaged."

"And living tissue needs blood," Morris added. "If there was a fracture there, there's all the tendons, the nerves and the blood vessels that a sharp edge of bone could cut. So, down the rest of the leg, there's no blood supply to it, so the tissue may die, let alone having enough blood supply to heal."

Even if there were a remote possibility that the bone might heal, it may not be a good idea to wait and see, because of the complication of laminitis.

Posted by at September 24, 2011 5:57 AM

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