Let's assume that all the horses were eaten before anyone could come up with the idea of domesticating them like what happened in the Americas (donkeys and zebras are still around). How does civilization develop without the horse? What would society look like without horses? What would warfare be like in a world without the horse? Could camels take the place of the horse?
buffalo, Oxen, Camels, Elephants, more human slaves.. humans are great draft animals.. tend to be a pain in the ass.. but if you work with them a little they are not too bad.
also remember that selective breading of animals could breed even larger versions of what we currently have.
