It looks like his diet was changed at least once, maybe more. A heavy grain diet, from grass, or whatever, will often times cause this. He will more than likely have problems all of his life off and on. I sold a man a young bull once, and the next day I met him in the road with his truck loaded down with grain. which he over fed, instead of giving him a light ration and getting him used to it. The bull limps off and on today, sometimes it is pretty bad. Has treated him for footrot a few times. I think I would pass on him. Glad you were looking.
buckwheat