Over the past several years, I’ve seen a considerable number of lame horses that have been diagnosed as having one problem or another but in reality have a very different one. And a visit a few weeks ago was no exception. I went out to trim a horse who’d been diagnosed with sidebone – the horse I mentioned in the post entitled What Makes it “Natural Hoof Care?” – and discovered that while he does, indeed, have some sidebone palpable in the lateral lateral cartilage (the one to the outside of the hoof) of one of his feet, it’s not his biggest problem at the moment.

Sidebone, just to remind you, is caused by excessive unilateral concussion – the horse repeatedly banging down on one “side” of his hoof. Since this horse’s conformation is such that his front feet point slightly toward the outside (as many do, especially in the hind legs), I’m sure someone tried to “fix” him by leaving the lateral (outside) wall longer than the medial (towards the horse’s mid-line) side. That’s the “time-honored method” advocated by many veterinarians and used by farriers everywhere to attempt to straighten “problem” legs.  In reality, the only thing it’ll straighten is your wallet as you open it to pay for work that ultimately compromises the long-term (and sometimes short-term) soundness of your horse! You cannot fix at the ground that which originates in the shoulder or hip. Unbalancing a hoof can only cause harm.

That said, I seriously doubt this horse’s sidebone will prove to be much of an issue at all, but we won’t know until the more immediate (and, unlike the sidebone, treatable) problem is resolved.

This horse, like the one I described in Progress!? and Progress Update!?, has a fairly serious infection in the central sulcus of the frogs of both of his front feet. If unrecognized and untreated, these infections can go deep into the frog, invading sensitive tissue and rendering the horse quite lame. Of course, that always leads to the question of how/why the veterinarian and farrier missed such an obvious (at least, to me) problem. I’m not, by the way, critical of the horse owners in such circumstances, because: 1) I have no reason to believe horse owners should necessarily recognize what’s normal for a hoof, and 2) I understand why owners assume they can rely on their vets and farriers to recognize what’s normal for a hoof.

How can you tell if your horse has such an infection? Well, in a healthy hoof, the central sulcus isn’t very deep; it generally looks more like a fairly broad “dent” in the middle of the frog, as if someone had pushed his/her thumb into it. Check out the photos in some of the other posts to see what I mean. The infected frog, on the other hand, has a very deep groove, hole, or “split,” often extending out the back of the frog. The hoof pick will go deep into the groove – a half-inch or more – and bring up a malodorous black “goo.” The horse will usually react to the pick, since the infection has invaded sensitive tissue, so be careful! A sure sign of the problem is when you note a dark line running from the back of the frog up between the heel bulbs and above the hairline. The central sulcus of a healthy hoof will never extend above the hairline. This can often be seen while the hoof is still on the ground, especially on horses with white legs. And scar tissue is often visible on horses who’ve had this infection in the past, appearing as a hairless line or inverted “V” above the hairline between the heel bulbs. The following two examples are of relatively minor cases; the horse in the first two photos is not yet showing any lameness, while the horse in the third photo is beginning to show a mild lameness. These were taken on my first visit: the first two post-trim, while the third before any work was done –

What, exactly, causes it? I don’t know for sure. But what I do know is that it’s most common during wetter times of the year, and that only certain horses in a group will get it, even though they’re all standing in the same mud. Clients ask me if it’s thrush, and I honestly don’t have an answer to that question because I’ve seen equine medical books describe thrush as both a white fungal infection of the frog and a black bacterial infection of the frog. In people, thrush is definitely a white fungal infection (of the mouth and tongue), so my inclination is to say “no, it’s not thrush.” There are a tremendous number of organisms – of all types – present in the soil, and I have no idea which one or ones are responsible for these infections. I do believe it’s bacterial, however, because it definitely responds to certain antibiotics.

It’s usually fairly easy to treat, although it can take a long time for the damaged tissue to regrow. Bearing in mind that I’m not a veterinarian, I generally have clients begin treatment with liquid Lysol mixed according to the bottle directions, and sprayed or poured onto the clean affected area once a day for 2 weeks. Depending on the severity of the infection, I also sometimes recommend making an effort to keep the foot dry with (preferably) a boot or limited turnout. After 2 weeks, there should be a noticeable improvement – the odor should be gone, sensitivity should be reduced, and new tissue growth should be apparent. If not, then I recommend the daily application of either of two over-the-counter topical antibiotics made for bovine mastitis called “Cefa-Lak ToDAY” or “Cefa-Dri ToMORROW” for 2 weeks. My clients report great success with this drug; as long as the horse isn’t perpetually reopening a very deep wound through the natural heel expansion that accompanies movement, there will be a definite improvement. In very severe cases, we’ve also had to restrict either movement (through stall rest) or hoof expansion (using boots) to get the wound to remain closed and heal.

One thing I don’t recommend is using some of the harsher chemicals people often use on feet, like chlorine bleach. It’s important to kill only the disease-causing organisms, and not new tissue growth. And, so far, the treatment outlined above has worked just fine, so my advice is to stick to it.

These cases apparently baffle many veterinarians and farriers, and every case I’ve seen has had at least one of each look at the horse prior to my involvement – sometimes several of each. Besides the sidebone case mentioned here, other misdiagnoses include laminitis/founder, pedal osteitis, and “navicular.” In a number of cases, the problem has been somewhat masked by shoes, often with full pads. Covering the sole with a pad, especially in conjunction with silicone poured between the sole and the pad, is particularly problematic because it traps moisture and seals out air, making a practically ideal environment for the offending (and often anaerobic) organisms to thrive.

So the next time you hear of a lameness issue, maybe you can pass this on to the horse owner. The real cause may end up being a relatively pleasant surprise!