Hoof Concavity: Why and why not? UPDATED PICS
I have a horse that only achieves concavity in his feet when he is shod. He typically goes thru the late spring/summer/early fall shod and I pull his shoes for winter. Within a few weeks of pulling them off he has grown out his nail holes and everything looks great - and he is sound thru the process - but he slowly loses concavity over the winter.
By this time of the year, he has lost almost all concavity. He also starts to become a little sensitive. His foot looks GREAT - balanced, heels back/under, toe short (he tends to not wear as short a toe as I would LIKE to see, but that's him) and his white line is tight.
My farrier thinks it is environmental - that when he has shoes on, I ride him on surfaces that encourage his foot to grow more concave, and that in the winter he is on softer surfaces and therefore he grows a flatter foot. He does not think it is a laminitis issue as it begins in the winter and progresses over the spring and he shows no other signs - he's certainly not a sinker.
So what gives? Any ideas? Obviously I would like him to have optimum concavity all the time!