If you run him year round, I’d sell him and buy a replacement ASAP. You’ll get slaughter price and that’s a shame but he’s going to be out of commission for a good while and you are going to need another bull. If you work a calving season and plan to have him pulled off the cows for a considerable time you can doctor him. Since he got it in his hind hoof (seems like a good bull never gets it in the front) and now in the other, he’s no use to you until those hooves are 100%. He will have to completely heal before you can expect him to take care of business.