Many dogs experience petting as a form of affection from humans, which makes these interactions not only pleasant, but even supportive of your dog's mental health. In fact, research shows that dog brains release the love hormone Oxytocin when they're petted and given attention from a human.

Although dogs love to be petted when they're awake, petting them while they sleep can startle them awake, and they can react aggressively. Constantly interrupting their sleep can leave them in a bad mood and at a higher risk of illness.

Although some dogs tolerate head pats, most instinctively feel uncomfortable when a hand reaches down from above their head.