For its Pals Rewards members only, Petco offers a Purina Pro Plan 13-oz. Dog Food Can for free via this printable coupon. (Scroll down to find the coupon. Not a Pals Rewards member? Click here to sign up for free.) That's up to $2 off and tied with our March mention as one of the best deals we've seen on this dog food. Coupon expires February 28.