She referred me to a nearby clinic that does laser therapy and we made another appointment with her in one month. I got pet insurance for Cai about six months ago and they should cover some of this. It will be my first claim with them, so I'll update here how it goes.
In the meantime, Chimera is on strict rest. He is not allowed to run, jump, or climb stairs. No fetch or retrieve training because he runs to get the object. He will be crated when I am gone, pottied on leash (to stop him from doing his usual sprint back to the door when he's done), and he is banned from getting in the furniture (I will probably have to use tethers a lot to keep him from jumping up). No heeling because he does a beautiful head-up position, which makes him lean back and puts pressure on the iliopsoas. His only exercise will be on leash walks and training that keeps him mostly stationary.
I guess I'll finally work on his stays, and maybe make more progress with matching to sample.