Old Cat Traumatized And A New Kitten

[Yoda and Vader]

So, awhile ago we took in a cat around the age of 2. Our original cat seemed interested in him but he was not interested in Yoda. He was sleepy and not very playful and Yoda is. A couple times when we weren't paying attention Yoda used the litter box and the other cat waited for him to come out and then would attack him and chase him away. We have since gotten rid of that cat.
We also have gotten a new kitten who is 3 months old. Yoda just turned 1 in March. Yoda normally is playful so we thought that once he is friendly with the kitten he will have someone to play with when we move out and don't have the cat our roommates have now, who he plays with, anymore. Yoda has taken to sitting on top of his litter box if we don't catch the kitten in time to keep him from using it but he neevr attacks the kitten. Lately Yoda has seemed not really skittish but more hyper-aware of his surroundings after the other cat was mean to him as well. He is getting along ok with Vader but he isn't himself. We are concerned and aren't sure what to do to help him get back to his old self and to get along with the kitten. Is it something that will just happen over time as he learns that the kitten won't attack him?

 

[Furballsmom]

Hi - has everyone, especially Yoda, been to the vet?
Also, take a look at these articles and the included embedded articles - hopefully there's something that helps you.

How To Fix An Unsuccessful Cat Introduction
How To Solve Litterbox Problems In Cats: The Ultimate Guide
Introducing Cats To Cats

Also there are calming products such as feliway and their varieties but this one, based on a pheromone, doesn't work for all cats (it has zero effect on my guy) so you could also try some other products, including diffusers, treats and collars available that have numerous types of different ingredients such as L-Tryphophan and casein.
Composure is a product to look at, Pet Remedy (it has valerian) is another, as is Essential Pet Pet-ease, Only Natural Pet (brand and website) has one under their brand and Pet Naturals does as well, and Lambert Vet Supply is a website to look at, and of course amazon and chewy.
--Even prescription if nothing else, --Gabapentin is good for travel, amitriptyline can help with general anxiety and OCD (such as excessive grooming).

Good luck!

 

[Yoda and Vader]

Hi,
Yoda has gone to the vet a billion times as I'm a worrier and anytime something weird happens that's where we are off to. Vader we just got on Saturday so we are going to take him soon once we get paid because we are both college students and not rolling in money. I have tried feliway before when we had the other cat and I also don't think that did anything so I don't want to try it again. Maybe we will try a collar version because food kinds won't do since we have him separated again currently but my roommates cat can get to his food so there's no guarantee he'd eat it.
Thanks!