Isn't being an equine vet physically demanding?
I've always been one of those people that found a way to work for myself, and do very well at it, as long as I put in the hours to keep money rolling in.
I think, if you are really looking for something that is easy on the body and pays O.K., you might look in to house pet sitting. I would make $45 a night to show up around dinner time, cuddle up with the house pets and give them love and food and some exercise, and then head out in the morning. All you are there to do is keep them company, so there's a lot of couch and TV time. That was a really cheap rate, most other companies charged 80+ a night. I just didn't see a reason to stress over it, when I got more than I needed.
Working part time hours during the day with some dog walking, and letting dogs out at lunch, along with a few nights a week doing pet sitting, I was able to make 2k a month.
So... that's probably the least physically demanding animal job I can think of.