If your cat went totally crazy hissing screaming and growling at you and trying to jump on you to attack and attacking its brother what could have made him do that?

Answer 1

* Was he around any catnip? that makes them hyper, he might have just been playing roughly. * Providing the cat was not in pain, or scared by something obvious, as far as I think, maybe he saw something you could not see, and it scared him. No proof, but I do think sometimes that animals may see, or sense some things that we cannot. * I agree with the above poster, but if this sort of action keeps up then you should take your cat to the vets to be sure nothing is wrong. Our pets aren't so far removed from us humans and can many maladies such as humans and (not scaring you here) but can have tumors of the brain or anywhere in the body, or possibly some pain in a part of the body.

* Possibility of territorial issues. My cat once circled my aunt several times, meowed at her and then jumped on my unsuspecting aunts head after she sat at his space at the heater and didn't move and as he was younger he was a bit wild and settled after age set in so age could be a factor too.

* I'm wondering if it has to do with the scent. When I brought back a cage with new kitten in it, even if I put away the new kitten in its separate place, I didn't realize I had big dog hair everywhere statically adhered to the cage bottom from the place I picked up the kitten. My female and male cats have been together since birth and always played with each other (spayed and neutered early on when they were in animal shelter). Well, my female cat is sneaky curious kind, male cat is totally playful alpha male, very friendly to strangers even! But when my female cat got in contact with bunch of dog hair, my male cat started hissing and attacking the female cat. I at first thought their hissings were due to the new kitten who were put away in separate room. But even without the kitten around at all, with cage put away, they started just attacking each other! (my female cat is very curious about the kitten, by the way. and my male cat's very scared of whatever that "thing" is behind the door). Well, I'm at my wit's end. Now I separated all three of them. I'm not even sure how I'm going to introduce which cat to which one first. But anyway, I suggest your brother cat might have picked up some scent that prevents the first one from recognizing him at all. * It's very important that you take your male cat to the vets as male cats can pick up parasites more readily than females. There could be some physical reason your cat is acting this way, so go to the vets first and if this is a territorial problem then your vet can help you remedy this. * Give him more cat nip eventually he will just pass out because he is just doesn't have any energy, or take him to a animal shelter, or just go all "old yeller"