I think those two loving owners border on kitty hoarders. Anyone with that many cats should know the basic of how to provide the right environment for them.
It must be wonderful to step out of that crowded, noisy, stressful clinic (not a criticism) and into the beautiful Colorado outdoors. What a reward and motivation to keep going.
Hip dysplasia surgery has come such a long way, and I'm grateful on behalf of dogs. 30 years ago my Lab needed help, and the specialty clinic talked me out of the surgery. There were message boards full of posts on how dramatic the surgery and recovery were, with mixed results. If you don't get the surgery, your dog's body compensates in other ways, like Thatcher's loss of muscle tone. My Lab compensated by shifting weight to his front, which caused other serious problems over time.