Full body wag
The big, body shaking wag means that your dog is very happy.
Behaviorist says: “The more swaying and wiggly motion closer to the head of the dog, the friendlier the dog is.”
Fast and shaky
A vigorous, shaky wag means a dog may be feeling aggressive and hostile.
Behaviorist says: “This is a highly aroused dog and should generally be avoided until it settles down.”
Wagging on the right side
Research shows that a dog wagging its tail on the right side is more friendly than on the left. You may notice your dog doing this when approaching you or another human they are familiar with.
Slow wag
A slow wag could indicate that a dog is unfriendly.
Behaviorist says: “Make sure to take the entire environment and personality of the dog into consideration. If it was an unknown dog, do not interact,”
Stubby tail
Dog breeds with stubby or curly tails still communicate just like any other dog. Make sure to pay attention to the base of their tail, which is where all of the action happens.
High and stiff
This generally means that a dog is alert and aroused for something like playtime. If other dogs are close by, it could also mean a pup is asserting dominance. When a dog is wagging its tail AND showing its teeth, you should leave it alone.
Curled toward the head
Certain dog breeds may just be relaxed in this state, as their tails have a tendency to curl toward their head already. However, if it looks like the tail is being pulled toward the head, it could mean that a dog is overstimulated and too excited.
Pulled down wag
If a dog is wagging its tail very low, almost between their hind legs, it is a sign that the animal is not very comfortable and might feel anxious.
Tucked-in wag
This tail between the legs look happens when a dog is scared.
Behaviorist says: “This can mean a dog is feeling threatened or is fearful of the situation he’s in. A tail tucked between the legs covers a dog’s genital area for protection.”
Limp tail
A limp tail could signal an injury. If your pup doesn’t seem to be using their tail at all, the little guy could be in pain and should be taken to the vet.