My understanding is you can make "yogurt" out of any liquid that can be thickened and has a decent sugar content to feed the starter bacteria. Yogurt makers are about $40 to $60 bucks depending on the brand, but the real work is getting the containers completely sterilized before you start so you don't grow nasty bacteria alongside it. I know Griff's wife makes goat yogurt from their goats, maybe she would have some pointers.
