To dream you are abusing someone suggests that your past actions will come back to haunt you. You may be expressing some regret or remorse over your actions.
To dream you are being verbally or physically abused suggests that you are feeling victimized in a waking situation. You are being taking advantage of.
Dreaming of animals being abused indicates that your own primal desires are being suppressed. You are unable to fully express an important part of who you are. Alternatively, the dream represents your helplessness in a situation.
To see children being abused in your dream implies that you are lacking a voice for your own inner child. You feel that a part of your own childhood is lost.