In the world of dreams the rules of reality do not necessarily apply. Each dream is unique and it's a direct link to the soul and spirit. Psychology provides its own theories on what dreams mean, but so did tradition and the study of dreams for thousands of years before any relevant science had developed.
Dream Meanings - Dog
To dream of a dog means love and friendship, especially if the dog is yours or a stray that obediently follows you or is happy. A white, friendly dog signifies great joy and happiness in love. If you hear a dog barking, then listen to the advice of people who want what’s best for you, but a dog acting wildly is a forewarning of fierce arguments. If it bites you then you will argue with your partner or with the person you are interested in, and a black dog especially shows that you will have great problems. A sickly or ill dog is a forewarning of illness or troubles while a howling dog forewarns of danger and you must watch out for accidents. To kill a dog is a sign of disaster while if the dog is dead then expect destruction and distress.