We have two horses with this. In Ranger's
case the cract is shallow and is probably related to his poor hoof
quality. Marla had a deeper crack for 6 years. Neither vets or
farriers could pinpoint a cause. Last winter she went grade 5 lame.
A quick exam, confirmed by the vet, showed an infection at the coronary
band. A few days of soaking and it drained. We then cleanded out and
opened the bottom of the crack. The hoof is now within a half inch of
being completely grown out without the crack.
Everyone's guess is that the infection had been
smoldering there the whole time.
Ed
Ed & Wendy Hauser 2994 Mittower
Road Victor, MT 59875