Personally it seems like you would rather be a vet tech. Why not do that for now, and go to school for canine rehabilitation later on or while you are working as a vet tech?
Why don't you want to be a Vet? That would be the best of both worlds, and a lot larger of a paycheck.
Also, I personally think it'd be harder to get clients for canine rehab, unless you did work as a vet tech first and talked to the clients at te vet office you worked at about it? Not sure, but I've never even heard of a canine rehabber honestly