From what I have experienced so far chicken wounds like this heal up very well and aren’t overly prone to infection.
I had some similar wound issues with a large rooster accidentally tearing open his girls backs. (He’s really gentle, just super big, inexperienced, and his girls weren’t really “into him” at first), and with one of my rescues who survived a raccoon attack, but her flock mates turned cannibal and wouldn’t let the wound close, so she was given to me to rehabilitate. As long as you can keep it from reopening or opening further it will heal. I mostly just leave them alone aside from the antibiotic ointment. You have a vet though, and they might be able to close up the wound better with sutures or by another method. Keeping it as clean as possible and covered with the ointment until your appointment won’t hurt. Looking forward to hearing an update as well.
