The farrier, however, has problems, because Siaga (my gelding) is terrified of farriers and can't seem to be able to stand still when one is around. (He had a traumatic experience with one as a youngster, where the farrier knocked both of his two front teeth out.) It's like he smells 'farrier' all over the person, be they male or female. As a result, his trimmings aren't always complete, and I often worry that something's not right, though he rarely shows lameness of any sort.
Anyways, the basic issue is this: When he was younger, his feet were very flat on the bottom. There weren't any large grooves under the heel at the sides of his frog. Now there are. They are almost, but not quite, wide enough for me to get my thumb in, and about 1/4 to 1/2 an inch deep. Is a change like that normal as a horse ages? Also, these grooves, which are the collateral grooves, are not all the same size, as if the frog is off center. I'm not a hoof expert, so I don't know if this is exactly normal.
The second issue is that on all of his feet, the frog is built out a little, like a callous, and also feels like a callous in that they are tough and firm, but do have some give. While I'm fairly certain that this is how they should be, when I look at some pictures on google of healthy hooves, it looks like the frog is not like this, instead looking a littler harder, almost like the rest of the hoof sole. His front left frog also seems a little tender, and from the heel forward toward the toe for about a half an inch, he has what I can only refer to as a "Hang nail" where part of the frog callus is somewhat detached. Although it is tender, he doesn't limp, and has no problem with doing whatever I ask of him.
So, I'm asking for input from someone who has a lot of hoof experience or a farrier, what should I do, if anything, and is all of this normal occurrence? (Other than, of course, his being terrified by farriers. I'm working on this.)