Would you consider skiing down a mountain knowing that if you broke your leg that would be the end of you? Me either. Hundreds of skiers suffer fractured legs every year in the US, and within 6 months most are walking without a limp. Yet we have all heard about horses that had to be put down because of a broken leg. What’s the story? Are veterinarians so far behind that they have to have to kill the problems they can’t fix?
In order to answer this question, let’s go back to the ski slope. Mary, trying to avoid a small child, veers off course, hits a patch of ice and is thrown into a tree. She struggles to get up, but can’t bear any weight on one leg. Within minutes the ski patrol has arrived, splinted the leg, and soon Mary is sledded down to an ambulance and on her way to the hospital. All the way from the slope and into the hospital, care is taken to insure that there is no leg movement. Within an hour of the accident X-rays are taken and show a complete mid shaft fracture of the femur. Complete means that the bone is broken in half. This is much more serious than just a crack through the bone. It is a bone in two pieces.
Muscles around a complete fracture go into spasm, which makes it hard to get the two ends into alignment. That’s the doctor’s first job. This requires muscle relaxing drugs to ease those powerful leg muscles. Appliances will be used to pull the bones into place. That process will take hours, perhaps days with Mary confined with her leg elevated by a system of cables and pulleys. Once the two ends are in alignment, a fixation system will be applied, which in this case will include hardware like rods, screws, and plates, and then, often, a full length cast. At this point the fracture is not really “fixed”. The bones have just been brought back into position and kept from moving so that the body can begin the true repair. If the blood supply is not too severely damaged and the reduction and fixation are successful, the fracture should heal, and Mary will be ambulatory.
Let’s compare Mary’s fractured femur with what happens to a horse with a fractured femur. The ones I have seen have happened in the winter or on slick mud. The horse slips and falls with one leg too far under the body. As the huge weight of the body is driven down on to that leg, the leg snaps. I have been called out in the morning more than once to check on a horse who has been down with a fractured hind leg all night. Often the owner and friends have been trying to get the horse up for hours before calling for a vet. The horse is usually found lying on the fractured leg. It takes at least three people to roll a 1000 pound horse over to the other side. Then, once the injured leg is on top it becomes obvious if the fracture is complete as the leg will bend in the middle like it never should.
If we suspect a fracture, but aren’t sure, X-rays will be necessary. Most equine vets carry an X-ray machine, but there is the problem of getting power out to the horse. Then there is the fact that the immense muscle of the quadriceps scatters the X-rays enough that a good radiograph with a portable machine is often not diagnostic. Machines strong enough to get through that mass don’t fit in a truck. With or without X-rays the animal still has to be transported to the nearest major equine hospital. This is no easy job if a horse can’t get up. If it is a complete fracture, we are faced with reducing the fracture. As with Mary’s broken leg, this would mean making sure that the animal be still for hours while the muscles are stretched out to get the ends back in position. I’m sure you get the point. All this can and has been done with horses less than a year old, but when I see a full grown horse with a complete fracture of the femur, I recommend immediate humane euthanasia. There is a somewhat better chance in dealing with the humerus of the front leg, but it would still be very challenging. I suppose if a 1000 pound horse fractured one of these big bones while in the operating room of an equine hospital there might be a chance. Even so it would be a very difficult repair with a guarded prognosis. Fortunately, big bone fractures of horses are rare. Successful repairs to date have been mostly limited to youngsters.
On the bright side there has been a tremendous amount of progress made in the last 20 years on bone fractures in horses. Cannon bones, and occasionally tibia repairs are successful with advanced orthopedic equipment in the hands of skilled surgeons. Horses with fractured pasterns that used to be considered hopeless now have at least a chance of being mobile again. Fractured coffin bones will usually heal in six months, but new techniques may have a race horse returning to work in half that time. Of course, part of the consideration will always be the inevitable huge cost on an uninsured animal.
Small animal orthopedic surgeons often repair every conceivable type of fracture in dogs or cats hit by cars. Dealing with horses is a completely different. The size and temperament of horses makes repair of big bone fractures impractical and often impossible, and so, yes, often we have no choice but to put these unfortunate animals down.
–David A. Jefferson, DVM