Body Language

From tail-pulling to ear-yanking, a dog can tolerate a lot. But his body language might reveal more about what he thinks of that kind of behavior.
Dog behavior can be lumped into three categories: enjoyment, tolerance and enough already (which includes avoidance and escape behavior as well as aggression).

Signs of enjoyment include an open mouth and loose body language. When there’s a break in the interaction, the dog will seek to start it up again. Tolerance typically is indicated by a closed mouth and minimal movement. The dog’s face is turned away, but he isn’t trying to escape. The dog is just waiting things out. When there’s a break in the interaction, the dog will choose another activity.

Warning signals (such as growling or staring) indicate a dog is in enough already mode and urgently wants to end the interaction. Lip-licking, yawning, turning away, shaking off (as if wet) and seeing the whites of the dog’s eyes are also signs it’s time to intervene and provide the hound immediate relief from the situation. Pay particular attention to escape and avoidance behaviors. If a dog moves away when you approach, he’s in Enough Already mode. Spend enough time observing your pet and you’ll learn to recognize the signals and act accordingly.

— Colleen Pelar, CPDT-KA, CDBC, author, Living with Kids and Dogs…Without Losing Your Mind.