There are a variety of skunk bags on the market that claim to be K9 proof, but there is no guarantee that any one bag will be 100% effective. The best way to protect your dog from getting sprayed by a skunk is to keep him away from skunks in the first place. If you must go into an area where skunks are present, keep your dog on a leash and be sure to have a bag ready just in case he gets sprayed.