My miny foundered a few years back, not sure the exact time period. He is still sound, to this day. It took about 6 months to get him back to normal. I haven't had any new problems with him since. We keep his hooves trimmed every three weeks. He is only used as a cart pony, so he also receives little exercise. I also only feed him plain oats, and grass when there is some and hay. Very little feed for him.
Hopefully your farrier approves. I feel like with the light exercise this horse should be fine.
"Courage is being scared to death - and saddling up anyway." ~John Wayne