If you can't make head or tail of Scruffy's behavior, his tail may give you some clues. This extension of your dog's spinal column functions as a useful emotional barometer, allowing you to take a sneak peek into his inner moods. Don't rely entirely on the tail though; this furry emoticon is only part of the puzzle.
Just a Puzzle Piece
When it comes to portraying emotions, dogs are very expressive animals. While you may be tempted to exclusively look at your dog's tail to get a picture of Scruffy's inner feelings and motivations, consider that the tail is only a small piece of the puzzle. Breaking down your dog's body language in components may be helpful; however, your final goal should be to put the puzzle pieces together so you can read your dog in his entirety based on the context he’s in.
An Old Wives' "Tail"
The belief that a wagging tail always depicts a friendly dog is a myth hard to debunk. While it's true that many friendly dogs will wag their tails when they are happy to meet and greet, it's also true that a dog who isn't wagging his tail can still be friendly, according to the ASPCA. To make things even more confusing, some dogs will wag their tails when they are feeling aggressive.
An Emotional Meter
Pay attention to the height at which the tail is held. Generally, at middle height you can assume your dog is relaxed. When held horizontally, Scruffy may be attentive and alert. Trouble starts when the tail is moved further up. A high tail can be a sign of excitement or arousal, but can also be a sign your dog is becoming more threatening. When things are taking a turn for the worst, you may notice your dog's tail held higher than normal while moving stiffly back and forth. Don't confuse this for a friendly, sweeping tail wag; if you look at the entire picture, you'll notice that everything else about his body language is suggesting that he's feeling far from friendly.
The Whole Picture
Keep an eye on your dog's tail and screen his entire body language before he's actually into Cujo mode and starts a fight. If your dog is getting ready to start an altercation, he may try to look large and intimidating. His head may be held high, the ears may be kept up and forward and his tail may be kept raised and stiff. He might flag his stiff tail nervously, moving it back and forth. You might also notice raised hair on his back and he may appear to be on the tips of his toes so he's ready to lunge forward. Staring at the opponent in the eyes, he may also show his pearly whites while growling, snarling or barking.
Not One Size Fits All
Your dog's tail won't have to be necessarily kept upright and stiff to denote far from amicable intentions. In some cases, dogs fight when they are fearful. Fearful dogs usually aren't troublemakers until they are cornered and have no escape. If your dog is fearful aggressive, he will cower, keep his ears flattened against the head and his tail will be tucked between the legs. Your dog may also show his teeth, bark, growl and even lunge and snap at the other dog, especially if the other dog doesn't back off.
To makes thing a bit more challenging, the tail carriage varies in certain breeds. For instance, chow chows and Chinese shar-peis have high, curvy tail, whereas, whippets and greyhounds have a natural low tail carriage. Some dog breeds may have a natural bobtail and other breeds may even be docked early during puppyhood. In these cases, you will have to learn to mostly rely on your dog's other body language signals.
Breaking up Fights
You may have heard about different strategies to break up dog fights. A common one suggests that you grab the fighting dogs’ tails while pulling the dogs upwards as if they were wheelbarrows. While effective, there are risks the dogs will turn around and go after you. Fortunately, there are safer ways to break up a fight, such as tossing a blanket on the dogs or using a hose to startle them and hopefully break up the fight.