Alert for possible danger on the path.
On Saturday we took our usual walk through the nearby wood. I turned the corner but after a minute or two, I realized the dog wasn't behind me. I turned to see her standing at alert, tail high but still. I looked to see what she was afraid of. Two English sheep dogs were coming toward her on the opposite path. "It's okay, they're your friends," I told her in a reassuring tone, but what do I know—I'm not a dog. Then the smaller, younger, of the two came toward her, tail wagging, and they exchanged sniffs. All was well.
We continued on our walk, with the two sheepdogs in front of us. It was then I noticed the larger of the two dogs had no tail. Not even a nub. Not a hint of a tail. It must have been an accident. Tail docking is no longer legal here, except in certain circumstances, but even a docked tail retains a stub. This one had nothing there. And I realized that was what the problem was earlier: The older dog had no way of telling my dog that she (or he) was friendly, and my dog was naturally being cautious, standing at alert attention until the larger dog's intentions could be discovered.
Dogs use their tails like a signal flag on a ship. In a dog book I have the author tells of his two Dalmations, one with a docked tail, the other with an intact tail. Despite the fact the docked tail female was the less aggressive of the two, the author had noticed she invariably was perceived by other dogs to be the more aggressive. A cautionary tale—excuse the pun—for those who'd like to dock a pup's tail.
Dogs only wag their tails when someone—human or animal—is around to see it, a hint that it's an entirely social and purposeful reaction. Nature has enhanced some dogs' tails, like mine, with light colored hair that is easier for other dogs and humans to notice. That's why so many dogs, pure bred and mixed breed alike, have white tips at the ends of their tails.
There are subtle differences in tail wags: recent research has shown that dogs wag their tails to the right when greeting their owners; to the left when facing an unfamiliar, possibly aggressive dog. The position of the tail also signals exactly how excited or relaxed a dog is, or whether they see themselves as "top dog" or in a more submissive role. Bristling tail hair is a sign of imminent aggression, while a broad, rapid tail wag means "I love you and want to lick you all over!"
Sadly, tail docking is still done by many breeders for aesthetic reasons, but it's unspeakably cruel—literally. With no long tail to wave in the air, dogs are left with little way of communicating. The pain may be over soon, but the deficit lingers on, as I saw on my walk Saturday.
Moral of this tale: Don't cut off your dog's tail.