I would NEVER buy one personally. I do remember reading somewhere (might have been on the forum) where someone said that only people who are very educated and familiar with the disease should ride even an asymptomatic horse, because they were most likely to be able to catch the signs and be able to get the hell off. So in theory you could learn what to look for... but personally I wouldn't risk it. Plus, I think that kind of experience with the disease comes from knowing many horses who have it and learning to recognize when a fit is going to happen - I don't know that you would be able to learn enough from books or the internet.

Snow White:     "How do you do?"

             Grumpy:   "How do you do what?"