There was a horse massuese type person who I used to know and she was really good at what she did. She did Bowen as well, and this light thing. Anyway she ended up being quite successful, and now lives in Europe or something and still has people working for her down here. You can make a fair bit of money doing horse therapies such as these but I think the key is being good at what you do, being honest and reliable. I've seen a fair few chiropractors around. The thing is you generally have such a small market that even if there are only two others working in your field and area, that can easily be too much competition.
I firmly believe though that if you are good at what you do then you will do well. Its not being good enough, its being good, and better than most other people, preferably all other people.
I know it seems ideal to get a job in the equine industry, but to be honest 95% of the time the pay is really crap. If you factor in your own rent, food, living costs, and then if you want your own horse, horse costs - there is going to be very little left to save up a decent amount for your own place. Even at the top places its not great pay. Lots of people are into horses, lots of people want jobs with them. If there are lots of people needing jobs pay doesn't need to be that high. I think you can earn enough to get by, but not own your own place.
Upnover - read what they said. Personally I don't think its a great way to get into horses cleaning out stables. The best way to do that is to successfully ride and probably compete and then maybe you will find someone wanting to employ you as an exercise rider or something, or someone will take you under their wing.
The people who I see who go the furthest in the horse business are those with great interpersonal skills. The kind that can just talk to anyone, make friends, and are memorable. I believe that the opportunities don't come through slugging it out cleaning stables, or an add in the paper, they come from people you know and people who like you.
I still think the best way to eventually own your own horse farm is to get an education and job in a paying field, then move to horses. I've seen a lot of riders or trainers with law degrees and such behind them.
My advice would be: get very good at what you do. If you want to do horse riding then ride, take lessons, compete, whatever. And get very good at talking to people - look into maybe an NLP course (Neuro-Linguistic-Programming) its basically a system that teaches you how to speak in a way that will influence people in your favour.
Think if its a life you want though. To me, struggling through years of working through stables with obnoxious clients and arrogant bosses, and dirt and early mornings and peanuts for pay does not sound like what I want from my life.