Posted by M. W. Myers, D.V.M. on March 09, 2003 at 17:31:01:
In Reply to: Big mess after prepurchase; need direction posted by Mary Ann on March 08, 2003 at 21:02:59:
: I hardly know where to begin. I'm a trainer that has an equine chiropractor for a client. She found a horse that seemed like a good project to her; lots of upper body problems, with some pain in the extremities. Sometimes, problems in the extremities are secondary to those in the back, shoulders, hips, etc. So she wondered if she fixed the back, could she help resolve pain in the feet? Since the horse pointed the left fore, I told her to have a prepurchase that included xrays of the navicular and hocks.
: The prepurchase was The Prepurchase From Hell. Everything we got, we had to ask for. These people were gracious, kind, and as helpful as they knew how to be, but they clearly were clueless. The horse was flexed and trotted on to squishy mud ground. Then I had to ask, "Can you flex the back ones, too?" "Do you mind looking in his eyes and listening to his heart?" Etc, etc. *sigh* The xrays were poor quality, but seemed to show a lesion on the right fore navicular. This was from a lateral view; the DV was with a shoe and pad. *sigh* (It was distressing to find the open textbook on what navicular disease looks like on the examining table). Also, both distal edges, where the deep flexor runs, showed some roughening. But I'm a trainer, and lack the judgment to know how serious the extent of the roughness was. I offered to the client to get a second prepurchase if she wanted. She opted to give the horse a try, and had him delivered. I told her then she should certainly have decent post-purchase xrays, for a baseline.
: Here's what the second exam found. Lots of carrots and lollipops on the distal edge of both navicular bones, the right worse than the left (he points the left). And three to four degrees rotation in the coffin bone on the left, more on the right. Vet examined a little further, and found scars from nerving on the right. Doc poked the heels with a Bic pen, and he didn't react on the right. We shaved the fetlocks, and found that the right had been nerved. It appears that for some reason, they passed on nerving the left. First vet missed both the founder and the nerving.
: His angles were 50 degrees on the left, 49 on the right. Both feet had contracted, undershot heels, but not grossly so. Frogs weren't too badly atrophied.
: Farrier took a look at the xrays, and did what he could. He has a rolled toe with a wider, longer base of support behind, and all the edges are safed. And pads. He also raised them as much as he could, which wasn't much. The poor guy was all in front of himself.
: I'm flabbergasted. I have no experience dealing with founder and navicular together. Clearly, the damage is great enough that any restoration up top isn't going to repair the damage in the feet. I don't know where to begin; I'm afraid if I advocate nerving, then once the pain of the navicular disease is removed, founder pain may show, and she'll have spent a bunch more money for nothing. He hasn't the comfortable use of his heels, and I question whether he'd have the use of his toes. Where's a guy to go?
: Do we start with nerve blocks to see if he'll go sound? Without knowing how or when he foundered in the past, what are the red flags and warning signs for this horse, with navicular and founder together? Do horses ever founder with that much rotation and go along uneventfully for long periods of time? Or should we just dump this guy as fast as we can? I'm just about as lost as I can get. Any help is welcome, and desperately needed.
The main question is what do you want this horse to do? If he is to be a pasture pet and occasional light trail horse we can proceed. If you want to show this horse, it would be prudent to look elsewhere. You are correct, chiropractic is not the answer for this horse.
One very big word of caution, NEVER denerve a laminitic horse.
That said, the horse is probably not laminitic, just severely mismanaged heel soreness. Allowing the toes to elongate for a protracted period of time can give the illusion of "laminitis" as the white line spreads from the mechanical stress. Denerving this horse and continuing the bad shoeing would lead to exacerbation of the navicular degeneration.
M. W. Myers, D.V.M.