Unsure why?

So my sweet cat, Jax, has been displaying some rather odd behavior that has been ongoing for the past month and has seemed to become more frequent. He is usually a sweet cat, full of personality and love, but lately he has become a mean, almost vicious cat. He has not been tolerating my roommate's two cats at all, finding any excuse to hiss or hit them (never uses claws). He will be sitting in the window and Yoda will come up to sit there and Jax will hiss and hit him until Yoda gives up and gets down. Jax could be sitting in the hallway and Yoda or Stewie will walk by and he will hiss and growl at them for no reason. The dog has become the cat's new whipping boy.... :( Noba provokes nothing and Jax will intentionally lash out at him for no reason. I'm not sure what to make of this. He seems to be feeling alright... his eyes are clear and his teeth are clean and his fur is shiny... he's up to date on all his shots... matter of fact, he got a clean bill of health from the vet in February. Any thoughts on this? I'm at a loss... I want my sweetheart back to his old self... :confused: :( :confused:

Has ANYTHING at all changed in the house around the time this behaviour started? Even if furniture got moved and he lost a favourite hiding place or something, this can cause it.

Also - even though he got a clean bill of health in February, another checkup wouldn't hurt. A tooth may have gotten sore, he may have a UTI that is bothering him and making him grumpy. Ill health can do that.

I'd say vet check first.

Then- I don't know how you feel about these things - but there is a wonderful pet psychic on here that many have used with great success.

Best of luck - I am sure your sweet boy will be back soon!

Wondering what you - and or roomate - do when he acts out. Do you rush over to him? Holler at him to stop? Could be he is getting attention acting up.

Can you try giving him a time out for 10 minutes in a small room by himself each time he acts up? He will learn there are consequences to his actions. Set the kitchen timer so you don't forget to let him out.

Or try using a water squirt if you can't do the time outs.

Then at other times, when he is calm and sitting peacefully, give him some pets and snuggles, maybe even slip him a tasty treat. Rather than 'leaving the sleeping cat alone," gently pet him. Reward him for the GOOD stuff.