It is possible to lead a cow upstairs but not downstairs

cow

Since cows have no depth perception, they will not walk willingly down stairs, as they are unstable on them. Cows’ eyes are on the sides of their heads, meaning they have panoramic, rather than stereoscopic vision. That is, they can see everything but what is directly behind them. Also, the cow’s knees will not be able to bend properly on its way down.