I know next to nothing about horses, but it looks like you're really good at the training. I'm enjoying the videos.
Excuse my ignorance, but will you be able to ride safely with THRs? I can't imagine how it might be to have to give up that part of you if you can't.
We have 2 dogs (and 2 cats). The older one is like your toy poodle, almost totally deaf, pretty poor sight, she also walks into things all the time. She's a Welsh Springer Spaniel, never the easiest to train with precision, she's got a bit of a stubborn streak in her. She's also very much "my" dog, she's only ever really listened to me, but now she can't hear and my hand signal training isn't as effective as it was since she can't see too well. Apart from not being able to get her to do what we want now, the problem for me has been the increasing frequency of toilet accidents in the house, really only about the last 6 months or so, but it requires bending to clean up and I'm struggling with that, and helping her up to standing, as she struggles so much to get up. She's quite heavy (about 25kg/55lbs). She was on metacam (doggy NSAID), but she got stomach bleeding, so we had to stop. It's really sad. We do keep wondering what her quality of life is now.
Please keep the videos coming, apart from anything else, it's inspiring to see what people who were in worse shape than me, can get back to doing.