First, aggression regardless of the reason is a serious issue. Cat bites can be deadly and when they happen, first aid needs to be addressed immediately. The good news is most cat bites can be prevented.
When a cat bites or attacks its owner unprovoked, it can be one or a combination of reasons. The most common reason is over stimulation due to too much, or not enough, play and/or petting. Cats are natural hunters, so it’s important to play with your cat routinely with a toy they can stalk, chase, catch, kick and bite.
It’s also important to read your cat’s body postures. Is your cat’s body posture indicating that he’s had too much play or petting? Respect their form of communication, and allow them some time to calm down before resuming play or petting.
There are several causes of aggression. In order to accurately diagnose the reason, a professional should be hired to observe the behaviors and create a plan with the owner and potentially the cat’s veterinarian.