Don't buy stuff under horsie brand names. They are three times the price of human stuff, and really don't work any better. Get human conditioners (I like Suave) and shampoos while they're on sale and stock up. For dandruff, use mouthwash. Soak your horse's mane with it, let it sit for a few minutes, and wash it off. A few days later, the dandruff is all gone. For leave in stuff, the most ghetto-est hair products you can find -- gels, conditioning spray, hairspray... It's all nice and cheap, and works great!