Aggressive Feral Tomcat viciously attacking my two male housecats

A year ago, I fixed a neighborhood feral Tom cat in a TNR (Trap, Neuter, Return) program and then he became tame and kept coming inside our house. He didn't have any aggression at all towards my other cats in the beginning when we brought him in, but gradually he began to attack the cats when they went into the litterbox. He got over that and now he randomly attacks the cats for no reason or when they are sleeping by biting their tails. The fights seem so vicious when they happen, but he doesn't draw blood at all, but my housecats scream so loud when the fights begin. I usually try to squirt him with a water gun if I see him heading towards the other cats, but I can't always catch it in time.

All cats are fixed, and I have tried separating the different cats into rooms, and letting the cats smell each other's scent in the room. I have also gotten a behavior modification pheremone spray, and I play for about half an hour each night to get him sleepy and less aggressive. He also receives an all natural calming support stress reduction supplement every time he attacks our other cats. (I got this from a local animal shelter thrift store) Also, I should mention that 2 of my cats are declawed(already that way when we adopted them), and 2 are not(which includes the feral cat. When we took the feral to get shots and fixed, the vet said he was approximately 13 years old. The feral has been inside now for a year now. He is very gentle and never bites us or scratches us, and is very possessive of the two women living in the house. I am open to any other suggestions to help with this aggressive behavior. Thank you.

RESPONSE:

It sounds like you are doing everything you can to help calm things. The feral is quite old and it is doubtful he will ever change his ways. And Lord knows what he went through on his own before you saved him! We also have a couple of cats that scream at the top of their lungs when they just see a cat they don't like. We have learned not to get too excited about the screaming unless it continues for a couple of minutes or there is a lot of thunking sounds that indicate a fight. 99% of the time it is just screaming occasionally followed by running. Try giving him his own "safe space" and be sure to have lots of high places and cubbies so they can all get away from each other. Also, be sure your other cats get plenty of attention and play time with you. It will help build their confidence and make them less inclined to participate in an altercation. Also, since the older cat seems to be becoming more agressive, a trip to the vet can't hurt. And make sure there are plenty of litter boxes in different locations so the feral can't guard them all. Otherwise, keep doing what you are doing and hopefully the feral will tire of the "game".

Donna - House Full Cats Mom