Dang Citrine, sorry to hear this. No help, but a possible consideration for the future: On our old houses we've found that often doing nothing is the best thing - you fix one thing and something else gets stressed and has to be fixed up. Investments are often best left un-tinkered with (supposedly). People who get one medical condition repaired seem to end up on a treadmill of medications as one med causes gas,which is fixed by another which causes sleeplessness, which is fixed by another which causes a heart attack, which.... Consider that kitties did, and do, just fine in the main with no intervention from us. They live, they die. We have some cats that are outside in the rain and some that come in. The ones that come in complain terribly if they are outside. The ones used to being outside are plenty happy if we come out and give them some attention, but don't act like they're gonna die if they don't get in right now. It may be that your kitties are getting too much of your focus.
But i'm an old farm boy - had a hard enough time springing for shoulder surgery for me (still not convinced it was worth it), can't imagine paying for repeated surgeries for a dog's tendons as CFB has been doing. Anyway, best of luck with Cassanova - and your art!