My cat suddenly attacked me viciously. Why is he so aggressive?
That must have been very scary for you! Yes, I would be very concerned about Boo Bear attacking you viciously, especially if this is out of character for him. I'm not sure what his vaccination status is, but (not to scare you but to put the fact out there), sudden aggressiveness can be a sign of rabies. If he isn't vaccinated against rabies and is allowed to go outdoors, then I would be concerned rabies is a possibility. I would take him into a vet immediately if he isn't vaccinated and allowed outdoors, and you should see a doctor as well as soon as possible. Cats have a lot of nasty bacteria in their mouth, and you can get a terrible infection from the bite. You need to be on antibiotics now to prevent this.
Other causes of his sudden aggression could be hormone related (I see he isn't neutered and he could be acting territorially), or a medical illness such as pain, an injury, or systemic illness. If he is up to date on his rabies and isn't allowed outside, then I would take him to the vet first thing in the morning. He should be examined by a vet to make sure there isn't a medical cause behind this sudden aggressive behavior. If it is hormone related, then I would have him neutered to help with that.
Updated on September 23rd, 2025