Likely a combination of factors, Lynn.
If there have been weather changes - dry vs.wet - that can play a role. It also looks like there is more wall length than there has been, which will crumble away, esp. when the wall isn't as well attached as it could be. More exercise increases blood flow and can speed hoof wall growth as well.
Bottom line is, you trim what is in front of you.
Lavinia, George Too, Calvin (PPID) and Dinky (PPID/IR)
Nappi, George and Dante Over the Bridge
Jan 05, RI