whether it's biotin or a brand name supplement, our farrier says it doesn't work .....period.
He says good hooves are genetic and biotin and supplements are worthless....
Hoof growth, capsule conformation and general quality is a product of genetics, associated metabolism, physical mechanics, environment and husbandry. Do supplements work? Sometimes, sometimes not. Like most things equine, it depends. It's like asking "how high is up?".
Would I personally recommend a hoof supplement for a horse as presented in the photos. Nope.
And both Beau and Epona's back hooves are pointed..... Is this normal?
Generally, yes. The hoof capsule will reflect the shape of the coffin bone to which it is attached. On most horses, the hind distal phalanx (coffin bone) tends towards more pointed as compared to the fronts. You are also more likely to see flaring at the heel quarters of the hind feet while the fronts tend towards dorsal wall flaring (dishing).
The reason is function. The fronts provide support. The hinds are responsible for propulsion and as such, their form follows that function.
While I might be inclined to clean up the excess bar growth, the photos present feet in generally good condition. Whatever your farrier is doing, let him/her keep doing it.