yes loosie.a boarder was feeding it's yearling too much alfalfa too soon in life,and the protein was making the hoof grow too fast for the leg to catch up.therefore,the hoof grew straight down from the coronet band.
I've heard of this happening too. What happens is the bones
grow faster than the tendons can grow/stretch, so the result is tendon contraction which results in club feet. Can't site where I got that, but I read about it on the internet when I was researching epiphysitis. My colt never got epiphysitis but as he was my first ever foal, I was trying to research what caused it so I could hopefully prevent it.
That being said, my young horse was basically raised on alfalfa. For the longest time I was trying to "balance" it out with bermuda. But my source of bermuda ran out so now I am feeding 100% alfalfa hay (with a small quantity of oats for the improved phosphorous ratio). He's almost 2 now so hopefully most of the epiphysitis danger has passed.