I was Slaughtering a bunch of horses and just couldn't stop
Dreams about animal slaughter can be quite disturbing and may indicate that you're experiencing intense emotions or feeling a sense of aggression or violence towards others. Horses are often seen as symbols of strength, power, and freedom, so to dream of slaughtering them may represent a loss of these qualities in your own life. Alternatively, the dream may be a manifestation of your fear of losing control or your inability to control your emotions or actions.
It's important to explore the context of the dream in order to get a clearer picture of what might be happening in your waking life. Are you experiencing stress or anxiety? Are you feeling like you're being forced to do something you don't want to do? It's possible that the dream is a reflection of these feelings. It may be helpful to speak with a trusted friend or counselor to help you process these emotions and find ways to cope with them in a healthy way.