New to this group, but not EC group.

I have a 5 yr old QH/App gelding (Boo).  The first week of April every year for the past three years he has blown an abcess on the R hind coronet band.  He'll be lame for 3-4 days, blow out and be cantering the same day.  He's on a dry lot, so I don't think it's diet.  Hay hasn't changed (bought a semi load of Timothy/Orchard mix in August), vitamins are the same (Pennwood's Equine Supreme), feed is the same (2 lbs Strategy with 4 oz Ground Stabilized Flax seed).   There is never any heat in the foot or leg, but swelling up to the hock, and some elevated pulses above the fetlock.  My farrier thinks we should resect the hoof yearly when he first shows signs, but I always 'forget' to call him.  There isn't a lot of puss or smell to the exudate, mainly clear, watery liquid.  Is this just something I need to set my calendar by.

Emily in NC