We've been having this problem too! Murphy ate through two leashes in four weeks. He would only chew on it while we were walking from the door of our apartment to outside (which takes about 3-4 minutes because of the elevator). But after a few days, it was almost worn through, and we were afraid it would break if he tried to take off after a bird or pulled too hard. So we took a field trip to Petco and bought him a nice lightweight chain leash (it has a leathery handle for the human to hold!). I think it was $11. Check out www.petco.com to see it. It has completely solved the problem. No dog wants to chew on a metal chain! And if he does, oh well...it won't do any damage.