A dog’s body and tail position act as an emotional meter. A horizontal tail indicates an attentive, alert dog. The higher the tail posture moves, the more threatening it becomes, with a vertical tail personifying dominance. Tail movement adds meaning to the position. Wagging speed indicates how excited a dog is, while the breadth of the tail sweep unveils either a positive or negative emotional state.
In a dominant posture, the dog’s ears are straight or forward. He holds his eyes wide open in an unblinking stare. His mouth remains closed or only slightly open with a low, assertive growl emanating. He stands tall and his hackles may be up as he drapes his head over a submissive dog’s shoulders. In this dominant posture, the dog’s tail is stiff and fluffed out, held straight out from his body and wagging slowly.
In an aggressive posture, a dog holds his ears back, close to his head. His eyes narrow as he stares challengingly at his opponent. Pupils indicate aggression and imminent attack when they suddenly dilate wide. His lips open and drawn back to expose teeth, the dog may snap his jaw and bark loudly in this posture. His body is tense and upright with hackles up on his neck. His tail is fluffed up and straight out from his body, making tiny, high-speed movements that almost appear as if it is vibrating as an indication the dog is about to run or fight. If the tail is held high while making this motion, it is most likely an active threat.
In a guarding posture, the dog’s ears perk up and stay forward. His eyes are wide open and alert. His mouth is slightly open with teeth bared as they gnash together. His body remains tense and rigid and he stands tall with hackles up. He holds his tail rigidly straight out from his body as he barks and growls loudly.
In an alert posture, the dog perks his ears up, turning them quickly to capture sounds. His eyes remain open wide while his mouth stays closed with teeth covered. He makes little to no audible sound, unless he deems a low whine or alarming bark necessary. His body stance is normal, though he may hold himself on his tiptoes in order to flee if needed. He keeps his tail up and wagging.