Ummm... I don't know about it bowing your legs... My legs look like they always had before I started riding, only difference; Im more flexible, and my legs are ten time stronger... I think if anything it would help dancing, not ruin.... But, that's just me.
Riding will actually help your balance and range of movement if you're a dancer. I did it for years...ballet, jazz, hip hop, tap..even clogging.. and there is no negative side of riding that will "bow" your legs. Yes, they may be sore and you'll walk funny for a day or so but you being a dancer should know that sore muscles work themselves out with stretching and using that muscle. If anything, it'd be a good exercise for you.
If you don't want to ride there are plenty of other things you can do that involve horses like the others have listed.