This one is exclusively reserved for dogs. Sure they make leashes for other animals, but try walking your cat on one. Just try it. Tell me how you enjoy the medical bills that follow.
Although leashes aren't their favorite things, dogs will and often do walk on them. You can walk a dog on a leash for hours without anyone thinking it's a problem or without your dog getting overly upset about it. But humans will definitely not walk on leashes. The next time you go for a stroll with one of your friends, try putting a leash on them. Just try it. And tell me how you enjoy the medical bills that follow.
There is an important exception, and that's lazy parents (often found at Walmart) who can't seem to keep their miniature human under control without tethering them. It's weird, but hey, at least the kids aren't clicker trained...or are they?
(flickr photo Furry Friday Dog by jessicafm;