Your new friend Joe has invited you over and you meet his tail-wagging Irish setter. What a good dog! As you lean down to greet him he tries to bite you. Oops. What happened?
Dog tails have originally been used to keep their balance as they turn or swim or run. However, they can also tell us a great many other things. Studies have shown that they convey fear, sadness, joy and hunger among other things simply by their tail wags. As to the questions as whether tail wagging is voluntary or not, you simply would have to ask your vet and he/she will tell you how quickly a puppy patient will tuck his tail to avoid a thermometer being stuck down there.
Some of the results of studies listed on sites from animalplanet.com and psychologytoday.com are below:
Broad wags: “I’m happy”
Slight wag with small swings: a tentative greeting
Slow wag halfway up: Insecurity
Wag to the right: Happiness, positivity or confidence
Wag to the left: Fear or desire to leave
There is more to a dog’s personality than his tail. Ears, eyes, and pinned back ears are also telltale signs of their emotions as well, and you should always be cautious with an animal you are not familiar with.