Tail Tales

Last week, it was sunny and warm. The leaves were bright and vibrant, and there was a light breeze in the air. Such perfect fall days are rare in Minnesota, so Maisy and I took full advantage of the beckoning lakeside trail. Of course, we weren't alone- many other people and dogs were out, too. Although I used to avoid the popular lakes when the weather was nice, these days, I don't worry so much about Maisy's behavior. Still, I do use caution- no sense in tempting fate after all- so when I saw a large, dark-colored dog heading our way, Maisy and I stepped off the path.

The man holding the dog's leash noticed this. “Your dog's not friendly?” he asked me as he approached.

“No, she doesn't really like other dogs.”

“My dog just loves other dogs!” he said, stopping in front of us, effectively trapping us in a small square of shorter grass. Maisy was sitting quietly by my side; the man looked at her, clearly hoping that I'd relent and let her greet his dog. Just then, his dog rushed to the end of his leash and barked. Maisy jumped up, her tail curled tightly over her back, moving tensely back and forth.

“Oh look!” the man crowed, as if he'd just caught me in a lie. “Your dog likes mine! She's wagging her tail!”

Ah, the Myth of the Wagging Tail rears its ugly head yet again.

Most people think that if a dog is wagging his tail, it means he is happy and friendly. This is not necessarily true. Yes, a dog wags his tail when he's happy, but dogs also wag their tails when they're feeling stressed, anxious, angry, aggressive, excited, anticipatory, and just about every emotion in between. A wagging tail doesn't tell you much other than the fact that the dog is alive.

Well, that's not entirely true. When Maisy wags her tail, it does give me some information. The height of the tail, the speed at which it's wagging, and the width of the tail's sweep as it moves back and forth all give me some insight into Maisy's emotional state. Let's look at each of these factors in turn.

First, the tail's height. Most people know that a tail tucked between the dog's legs means he's scared, but once the tail starts moving, they seem to quit paying attention. In general, the higher the tail, the higher the arousal level. The problem is that normal tailset varies widely from dog to dog. For example, Maisy's tail is naturally curled up and over her back, so her low tailset looks very similar to a greyhound's high tail. Maisy's relaxed tail is therefore physically identical in height to the greyhound's excited tail.

So we move on to look at the speed at which the tail wags for more information. Just as people breathe quicker when they're excited, so does the dog's tail move faster. Slow, deep breaths are common among relaxed people, and likewise, slow wags usually indicate more relaxed dogs. Of course, that doesn't tell you anything about why the person (or dog) is excited. Did they just win the Super Bowl? Have sex? Kill a person? Who knows!

For another clue, though, we can look to see how wide the sweep of the wag is. By this, I mean how far the tail moves back and forth. A tight wag may only move an inch or so, and generally happens when the dog is feeling tense or stressed. Meanwhile a loose one can go so wide that the tip of the tail touches both hips. Sometimes a tail will be so relaxed it moves in a giant circle (we call that “helicopter tail” around my house).

The height, speed, and sweep can come together in many ways, creating a large range of possible combinations. For example, a high, fast, short wag indicates high arousal. This was what Maisy's tail looked like when the dog at the lake barked at her. She was very stressed, and part of how I knew that was because of the way her tail was wagging. But I've seen this same combo of tail features in other situations, too- while playing with another dog or when anticipating a ball toss- all of which are high arousal times too, just for very different reasons.

So while a dog's tail can tell you a lot about his feelings, you still need to look at the context. When the tail is read as part of a whole, it makes far more sense. A high, fast wag looks very different when the rest of the body is very still as opposed to being wiggly. Pinned ears makes a low tail look nothing like the same tail paired with perky, alert ears. And of course, I happen to have enough history with Maisy to know that a tightly wagging tail when a large, black dog is around is very different than the one that happens when she's playing with her kitty.

The man we met at the lake didn't have that benefit. He had no way of knowing that Maisy detests dogs that look like his, and it's a fair bet that he didn't notice her stiff posture. It would have been nice if he'd believed me, of course, but given her still body (which is easy to mistake for calmness), I guess I can understand why he thought Maisy's wag was friendly.

I knew it wasn't, though, so I very deliberately stepped between my dog and his, and repeated, “My dog does not like other dogs. I'm sorry, but she cannot say hello to yours.”

The man looked crestfallen, and maybe a bit confused, but he did leave. I breathed a huge sigh of relief, and Maisy and I continued on our walk, too. As we put distance between man and dog, Maisy's tail began to loosen, her body softened, and her ears relaxed. She looked up at me with sparkling eyes and a big smile, and I knew that now her wag was happy.