Put a large flight animal in a domesticated setting, surround him with walls and fences, ask him to suppress millions of years of evolution and instinct in order to cope with his surroundings, and you are going to run into trouble. Sooner or later. Guaranteed.
But even the horse in the wild is at the mercy of his physical structure and evolutionary development. He’d better keep eating and drinking, because his digestive system does not Do stoppages (if it stops, it kills him), and that foot structure, while decently designed for shock absorbency and for holding up through a lifetime of running on steppe or tundra, can still wear down too fast if the ground is too hard or rough, or break down completely in excessive heat, cold, or in response to illness or infection anywhere in the body.
For the human managing the domesticated horse, one major brain-stumper is the Mystery Lameness. That’s the horse who is lame without clear cause, for whom even modern veterinary science may not always have a clear-cut answer. Or there seems to be an answer, but the treatment doesn’t seem to make any difference. It’s like an episode of “House”: every time you think you’ve figured it out, something new blows up in your face.
Mystery lameness can show up in any number of ways. It may be a slow creep–he’s fine when he walks but his stride is short when he trots; some days he’s moving sound, other days he’s gimpy; if he’s on his own he’s OK but if he’s being worked or ridden, he’s what horsemen call “off.” Sometimes it’s clear which foot it is, sometimes it seems to move around, and sometimes it’s a general not-quite-rightness. And sometimes it’s a sudden, acute, crippling lameness that could be anything from a serious injury to a hoof abscess building up pressure and about to blow–and if it is an abscess, it could be the result of injury to the foot, or an injury elsewhere that caused an infection to travel downward and erupt through the foot, or a reaction to excessively wet or dry footing (either one is not a good thing).
With an abscess at least, once it’s found and lanced and the infection drawn, the lameness usually disappears, then it’s a matter of keeping the foot protected (in a wrap or boot) until the hole in the sole heals. But then there’s the question of whether there’s something else going on to cause the abscess.
Horses can’t talk, which complicates matters, sometimes considerably. They will signal that there’s something wrong, from classic limping to nipping or flinching when touched (or even holding up the injured foot and shaking it), to a generalized crankiness or bodily tension. But they can’t say in so many words, “Damn it, my FOOT hurts!”
To add to the fun, pain or trauma in one area can manifest in another. It’s quite common for a sore foot to look like a sore shoulder, or vice versa. Or sore front feet may look like sore back feet because the horse is shifting his weight off the fronts to the hinds, and the hinds are sore from carrying the extra load. Or a sore foot in one corner may seem to be a sore foot on the diagonal corner (left front/right rear, for example), again because of the unbalanced weight.
Even advanced diagnostic equipment can’t always find the problem. Something relatively simple like a broken bone or a torn or ruptured tendon, yes–but if it’s in the shoulder, for example, maybe not. The horse is a big animal, and imaging can’t always penetrate that much muscle and bone. In cases like that, one has to fall back on good old seat-of-the-pants diagnosis, along with such traditional standbys as palpation, manipulation, walking or trotting out, asking the horse to move on different footing (hard, soft, rough, etc.), or for those in less low-tech but still not high-tech settings, nerve blocks: injecting each section of the leg in turn with an anesthetic and then asking the horse to move out, and noting at which point the lameness disappears.
There’s something called a “flexion test,” too, which can find arthritic problems or tendon or ligament soreness: flexing each joint tightly for several minutes, then asking the horse to trot off immediately on release. This is a bit controversial in some quarters, on the principle that anyone who has his leg cramped for several minutes is going to hobble when he takes off, but many vets swear by it as a simple diagnostic tool. If he doesn’t stop hobbling after a couple of steps, the reasoning goes, then there’s something not right in there.
Even if it is possible to pinpoint the location, it may not always be possible to figure out exactly what’s going on. If the leg is sore, is it the primary problem, or is something going on elsewhere that is causing the leg to be sore? If the horse is lame under saddle but not on his own, is it a poorly fitted saddle, a sore back (either from the saddle, the riding, or an unrelated injury), or even pilot error–the rider doing something to cause the horse to move out of balance? And it’s even possible for him to be lame on his own but not when ridden–if the rider is correcting the imbalance either consciously or unconsciously while the horse moves.
And then there’s the question of what to do about it. Wrap the sore tendon? Massage the sore muscles? Administer painkillers? Anti-inflammatories? Treat the arthritis with drugs, feed supplements, PT? Almost always, at least part of the prescription is some form of rest–in a stall or small paddock–but that presents considerable challenges when the patient is a large herbivore designed to move constantly across a large range, and emphatically not designed to stay still for any length of time, or stay sane doing it.
Calming potions may help, likewise low doses of tranquilizers, but those present their own problems related to dosages and side effects. And even if they aren’t needed and the horse tolerates confinement well–what happens when he’s healed (or seems to be healed)? How will he react to his freedom? Will he get overexcited and reinjure himself and need to start all over?
It’s a conundrum. And a mystery. And sooner or later, every horse person has to try to solve it.