Young attacking old

Our 1 year old has been attacking our 12 year old for about the past 2-3 months. At first we thought it was her playing but now it's turned more vicious, she'll just run up to the older cat and swat at her. The older cat will always enter a room with caution, hide behind chairs, move super super slow motion if the little one is near. I do punish the younger one by giving her a firm "no" and time out in another room. Then the cats will both sleep with me at night and at times seem to get along just fine. I'm not sure if this is a phase or if there is anything else I can do to remidy the situation.

I should mention that the older cat will run and I think this excites the little one to chase. The little one tried swatting at my eldest cat, 16, who does not run from her and I don't have this problem between them.

It's like the little/younger one knows it can beat up on the 12 year old so it takes full advantage of the situation.

ideas?

Welcome to TCS!

Take the older cat to the vet for a full exam & blood panel. Often, younger cats will try to drive away the older ones when the older ones are sick/dying. You may not notice anything off in your older kitty, but cats are excellent at hiding pain.

1 year olds can be rambunctious and she might just need to outgrow it.

But I have to ask: how long have you had the younger cat? If you've had her since a kitten and this has just started in the last few months, I would take your 12 your old to a vet for a full health screening, including a geriatric profile (bloodtest). Younger cats will attack an older cat that is ill. And since cats are usually so good at hiding when they are sick, often times you find out about an illness by watching the behavior in the other cats.

It never crossed my mind the 12 yr old could be sick. Good point.

I've had the 1 yr old since she was a baby, 12 weeks. She is very jealous, every time the older cat jumps on the bed to come get some attention the little one will be right behind her, or the little one will lay in the older one's spot just when she knows the older one wants to lay there. Or if they are outside and the older one wants to come in there will be a swatting battle at the cat door.

When my 2 other cats come to get attention from me I can see the young one will stop what she's doing, starts hanging around, inching her way closer and closer, encroaching in on the other cats attention time. She just does not dare fully interrupt because she knows they will beat her up. The young one also follows me everywhere I go, into every room of the house. None of my other cats do that.