I just wanted to provide an update. Our poor bunny made it to our rabbit savvy vet a few days later and we showed her all the bandages, tissues, and the towel that we had to use to stop the bleeding. The vet was shocked at how much blood there was, and said that he must have had the sore really close to a small artery or something, and when it busted open, it bled more than it should have. Thankfully, by the time we got to the vet, about 48 hours after the incident, it was completely healed and the foot was totally clean (which shocked me because we did not clean the blood off because we were afraid it would bleed again). Our vet started flocillin shots once a week for a few weeks, and we decided to leave the litter box out. We replaced it with a small tray, and just put in plenty of newspaper and hay to catch everything. We are 19 days out since this incident, and at the last appointment a few days ago, the vet said this is the best they have ever seen his feet (front and back) even though we have battled with sores on the front paw for months! So, they think that the combination of removing the litter box, changing the hay to a softer hay (we switched from Timothy to Orchard Grass), and now the flocillin shots, that maybe we finally found the permanent solution to the sore back hocks and the front paw that wouldn't heal! I am updating in case anyone else is dealing with similar problems with sore hocks.