This is not a service that most pet owners would want, but certainly anyone who does agility or flyball, racing (greyhounds or huskies), heelwork to music and even showing often have their dogs treated. The main problem you will find is getting known, as most people have their own 'physio' and some people travel miles to the top ones. I use a lady who does Reiki on my dogs and have taken them to her if they seem to be in any sort of pain. One of my dogs is quite clumsy and sometimes runs into the others, putting their backs out of sync or similar injuries, and she does about a half hour session, just gently manipulating their muscles along the back and neck and they come out feeling much better. Will try to find a link. McTimoney is another type of treatment. As for cost I only pay £10 per session, so you are not going to get rich from me. I would suggest you start by joining some dog training clubs and go from there. Advertise in catalogues of breed shows, or maybe in the dog papers/magazines.