Sorry for a bit more of a delay in getting this posted than I’d intended, but between managing clients, the end of the school Quarter, and attending the Berkshire International Film Festival with Annie last weekend, time has been tight. But hopefully you’ll find it was worth the wait!
I’ve discussed some of the effects of deliberately manipulating hoof angles before – particularly in Hoof Angles – Part 4, where I described some of the consequences of imbalance on bones and joints. And while I firmly believe proper balance and length are absolutely crucial to the long-term comfort and soundness of a horse, that doesn’t mean appearances can’t be deceiving. Take a look at the following photograph of a client’s horse –
At first glance, you might conclude this horse is out of balance. After all, a 10° difference in a pair of hooves is pretty significant! But in reality she’s not. Remember: hoof form is the consequence, and not the cause, of movement. So when we see this situation in a horse that’s properly trimmed, we have to look at what, in her stance or movement, might be causing this particular asymmetry between her hooves. Now, a logical question at this point would be to ask how I know this horse is properly trimmed. And the answer, at the clinical level, is because her hooves grow straight, without any flaring, thickening, or other distortions, and because she lands flat at the walk. That confirms proper balance; it’s not subjective, and it can’t be faked.
As further evidence of proper balance, let’s take a look at a radiograph of the upright hoof, which the veterinarian labeled a “club foot” –
It’s generally acknowledged that the plane defined by the bottom of the coffin bone should form a 3° – 5° angle with respect to the ground surface. As you can see on my protractor overlay, this angle appears to be just a bit higher than that – about 6°, or 1° higher than what’s considered correct. Not 10°. Not even close!
To be fair (to both the veterinarian and myself), we need to acknowledge several things about this radiograph and the conditions under which it was made. First and foremost, this hoof needs trimmed, and doing so will almost certainly drop the angle another degree or two. Second, note the very slight divergence in the toe angle; while the upper part of the wall is growing out nice and parallel to the dorsal surface of the coffin bone, the lower part still has some growing to do. Third, you can see where the tip of the coffin bone has deformed, taking on what’s usually called a “ski tip” appearance. More on that later. And fourth, I had to tip the image slightly because the horse wasn’t bearing weight on the foot when the radiograph was taken; the heels were off the ground. The implication of that is an almost certain decrease in the hoof angle, because the digital cushion (a shock-absorbing mass of fibro-fatty tissue – see below) at the back of the hoof compresses slightly as the hoof is loaded.
All of this adds up to a hoof angle that’s darned near perfect, regardless of how different it is from its mate!
So why is it steeper than the other hoof? Well, that’ll have to wait ’til next time. But let me just say that the veterinarian’s recommendation for this horse was to lower the heels on this foot – into living tissue, I might add – to make them match and “fix” the problem. No way was that going to happen!