Dreaming of beating a dog is a negative sign as per dream meaning and interpretation. The dream means you taking out the anger on someone on an animal or thing or a stranger. It means anger and frustration. It also means you getting scolded or accused of something. Dreams of beating a dog also means something you had thought would be good for you will soon turn into a nuisance.
Dream of beating a dog and the dog is still lying in the same place means in spite of all your efforts you will not able to solve a nagging problem. It also means getting into trouble through an action which you thought was normal.
Dreaming of beating a dog and the dog fighting back means you will be attacked by animals. It also means you undermining the strength of the opponent and this causing embarrassment and damage both physical and mental.
Dreams of beating a dog and you see lot of dogs means you causing problems to your community by attacking someone who has the backing of gang or community.