First of all, you may be under a lot of pressure (including emotions) in your life, work and study recently, almost to the limit. I hope you can find out the reason carefully and adjust it in time.
Of course, someone has upset you, made you angry and unhappy recently, so this kind of thing happens in your dream. Beware of villains and pay attention to traffic safety when traveling.
I usually have this dream when I am in a bad mood or too tired, and I feel the same way. In short, be careful in everything, be patient with people's contradictions and avoid quarreling.
Dogs in dreams generally represent bad people and troublesome villains, and others have no special meaning.
In your dream, you dreamed that the dog bit your sister and bit her badly. Dreams are just the opposite of reality, indicating that the bad things in reality have been lifted and you can live a normal life with peace of mind.