I attended William Woods University in Fulton, MO for one semester. They have an Equine Science degree and an Equine Business degree. It is a good school over all, but it is VERY expensive, it's an Ivy League school. In my opinion, it was not worth the money. It is great if you wanted to major in something else like Law or whatever and just wanted to minor in horse stuff. But it is not worth it for just the horse stuff. You won't learn to be a trainer there. You will learn to teach CHA very well, but there is no training. I was only about to ride two or three times a week and only worked in the barn a couple days a week (those positions were limited to those that qualified for work studies. Not nearly as much hands on experience as I wanted.
I ended up leaving there and got a working internship at a dressage training barn, which in my opinion is the best way to go. I was there for seven months and learned more in that span of time then I did in the previous three years combined. I lived and worked on the farm, got to ride multiply horses a day, I became a part of their team and got some REAL WORLD experience. I got to train young horses, I got to ride stallions, I got to help birth foals, it was amazing! I also had some opportunities to show for free.
Right now I am applying for an apprenticeship at another barn. That is the cool thing about getting your education that way, they are usually short term, anywhere from 6 months to a couple years, so you can do multiple internship to make yourself a well rounded horseperson.
If you want to become a horse trainer or riding instructor (or horse manager, or groom, etc.) I HIGHLY suggest that you find an internship, apprenticeship, or working student position. It is FAR less expensive (in my case it was free and I got free room and board in exchange for my work) and you will get much MUCH more experience.
I'm tell you right now, you will never need a college degree to become a horse trainer or riding instructor, people don't care about your GPA in those positions, they want to know how well you can ride, how many horses you have trained, and how enjoyable you are to work with (meaning you need to have a good code of ethics, it goes a long way in this industry, trust me. Slander and backstabbing are popular in the horse world, but if you abstain from that junk people will notice and THAT will get you ahead. Just a side note).
You said you want to do Psychology in case horse training does not work out... Do not take that stance, DO NOT have that mind set. It is pointless to have a plan B if you want to work with horses. You know why? In order to do well in the horse industry you have to go after it wholeheartedly, you have to want it more than anyone else around you wants it. If you spend a lot of time setting up a plan B then that is time taken away from your main goal, meaning you don't really want it as much as you say you want it. Those that really do well in this industry are those that are willing to work hard and step out of the traditional mold that society has set. If you set up a plan B then you will fall back on it as soon as times get tough, and trust me times WILL get tough. But later on you will regret not sticking with it, that is if horses really are your true passion. You need to decided if horses are what you really want to do with you life. Do you want to be a trainer? Or do you want to be a Psychologist? You need to make up your mind.
Now, don't get me wrong, college is great for your overall development as a person. I did not graduate from college, but I spent three years taking basic core courses before I transfered to William Woods, I have a fundamental education that I am very thankful for. If you are hesitant about going cold turkey and not going to college then I suggest you go to a community college and get an AA or something and then go work an internship (in some cases, you may be able to do both at the same time if you work part time in each). You will save so much time and money in the long run.
Here is the thing, when you graduate from a "Horse College" you are still going to have to get a job and work from the very bottom up. So why not just start out from the bottom and work your way up while learning on the job?
Think it over, start looking around for internships, apprenticeships, and working student positions. Check out www.yardandgroom.com
They have lots of postings all over the world for internships, apprenticeships, and working student jobs (as well as any other horse job you may be looking for later on). Start talking to trainers that you are interested with. Don't be afraid to send them e-mails and ask questions about the industry. Be willing to step out of your comfort zone. Look for every opportunity you can to ride and work with horses. A career with horses does not come easy and it will NOT just come to you, even if you go to a top horse college. But if you chase after it, you CAN achieve it.
Good luck. If you have any more questions and want to talk to me more about what I have done and what I am doing, don't be hesitant to PM me. I am still in the thick of it, I'm not a professional yet but I am well on my way and am tacking active steps to get there. It is very exciting!
Sorry for the long post,