Hmm. Just read some more.
From the website, it lists symptoms as :
Microorganisms do not ordinarily attack healthy hoof tissue. They usually gain entry via a hoof crack or fissure at the white line. Other predisposing factors include:
Abscess formation that introduces infection
A case of laminitis that causes tears in the stratum medium
Sole or toe bruising near the white line where dried blood provides growth nutrients for the causative organism
Flexor deformities in foals that have resulted in club foot with severe toe bruising; long toe/no heel syndrome in which an excessively long toe with a stretched white line has weakened the bond between the medullary cells and constant exposure to manure and urine.
The only one that I can see there is the seperation
(Diesels foot looks similar to this picture, but as far as I can tell, the sole isn't as concave)
Apparently it's a fungus too? That makes me think there should be something removed/treated? (Of course, I am neither vet nor farrier). He is on dry-lot with turn out a few hours a day on grass until we get the pastures completed and not in any mud or wet...