The tops of the nails used to be more flush with the hoof, now they seem to be working their way up out of the hoof. So, "up" as in "not down in the hoof".
Farrier has a good reputation because he's certified, competent, and good with the horses. The vets approve, and there are a lot of horse people in this area who respect him, so it's not one of those things where he's the only game in a 200-mile radius. There's another farrier who is popular for horses that have soft or crumbly hooves. My guy isn't in that category, or wasn't, as recently as September when he had his vet check (vet states on the report that his hooves are in great condition) and when the farrier came out last - horse is due for his regular trimming/shoeing/whatever in 2 weeks, so this is not a new pair of shoes or a recent trim. It's a couple of months old. He didn't used to have a crack there. I pick his feet out and clean them up at least every other day and this is new.
Given how much the mud in the paddocks was sucking on my boots, I'm wondering if it's starting to suck the shoe off his hoof. He has a real love for a mud-wallow, even if it is not super muddy, he'll trample and dance on a dirt patch until it turns into mud, the little piggy. Maybe the muddy conditions - it's been disgusting for I don't even know how many weeks on end - made this shoeing have a shorter life than it usually would at this time of year? Also, he's been getting into fights with the horses in the turnout. Maybe this is some kind of weird Battle Scar?
Just as long as it doesn't look like laminitis, or any of that other awful stuff, that's what I needed to know. I haven't actually seen any horrible hoof diseases, I just know that some hoof problems are little issues and some of them are very bad, and I do not have enough experience to know the difference. I'm sure that if the other more experienced horse owners had been around lately, they would have been able to sort it out for me, it's just that things have been very difficult for everyone and playing with the ponies is not at the top of the list when you have no heat or water. :( I am lucky that I do.