Eyes, face, mouth

A soft eye is slightly squinted, the lids relaxed, blinking normally. It says, "all is well". A hard eye is wide, lids pulled back, no blinking, pupils often large. A hard stare directed at a person or another dog is a serious warning. It usually comes bundled with a still body and a closed mouth. If a dog you do not know gives you a hard stare, the best response is to slow down, avoid leaning in, and give the dog room to choose.

Whale eye, sometimes called half-moon eye, happens when a dog turns its head away from something but keeps its gaze locked on it. The result is a crescent of visible white at the inner or outer corner of the eye. It tells you the dog is uncomfortable enough that it wants distance, but is still tracking the thing that worries it. A classic trigger is a child hugging the dog around the neck: the dog leans away, eyes whale-eye to the side. That is a please-stop signal, not a cute photo.

A quick tongue flick that shoots out and up over the nose, then retracts, is a classic calming signal. So is a wide yawn in a context that does not fit sleepiness, like sitting in a busy waiting room. Both help the dog self-soothe and also signal to others, "let us slow down". A single lick after a meal is not a signal. A lick with no food around, often repeated, during a stressful moment, is. Same goes for yawns: one after a nap is just a yawn, three in a row while a stranger bends over the dog is a message.

Heat panting is usually rhythmic, the tongue hangs loose and long, the corners of the mouth are soft, and it slows as the dog cools down. Stress panting is often faster, shallower, and starts without a temperature reason. The tongue may be flatter or more spatula-shaped, corners pulled back, mouth tight at the edges even as it hangs open. If a cool dog in a cool room is panting in a vet waiting room, assume stress first and look at the rest of the body.

A relaxed mouth looks slightly parted, jaw loose, tongue resting or gently showing. Many people call this the "doggy smile". Matched with soft eyes and a neutral tail, it is one of the most reliable all-is-well signals. When a dog suddenly closes its mouth, especially in a social situation, that is a change to notice. Closed mouth plus a stare plus stillness is often the last moment before a growl or a lunge. A soft open mouth is your green light to keep doing what you were doing.