Yes, interesting. I have never even seen a CWD in the wild but have heard about monodactyly in deer only once before - about 20 years ago my guest shot a roe buck in North Galloway with a similar slot. The buck was in perfect condition, the other 3 hooves and antlers were normal.
I guess it's just a congenital deformity in the same way X in every 1,000 people have 6 toes (polydactyly) The guest is German so thought it was great and it's mounted on the shield with the head. I'm afraid it was before the days of digital cameras but I will ask him to photograph it on the wall.
must be a Norfolk thing?
were the other hoofs webbed?