Advice about new cat attacking older cat .

A question about : Advice about new cat attacking older cat .

We have two cats, one female 17 yrs and one male , 9 years . Have had the 9 yr old about two years and there's no trouble between them . Our sons cat , male , 6 years came to live with us 3 weeks ago . He'd become stressed at sons home and messed on the beds , sofas etc and hid under the bath for 2 weeks . We've been able to keep him in a bedroom with litter and food . He's been fine and started to come downstairs sometimes in the day . He's been near to the other male , no attacking so far . The female and him have growled at each other but today he leaped on her and pulled a mouthful of fur out . She ran behind the sofa , he waited and jumped on her again . He seems to be watching for her making a move ! She was terrified and he was so quick I couldn't stop him . She's always been a very timid cat and has been bullied by our previous cats , they've died now . Until today I thought it was going well. He's ran back upstairs and she's come out of hiding to sit beside me again . Anyone been in this situation before and did it settle down ? I don't want poor timid Beattie to have to spend her twilight years in fear .

Best answers:

• This should explain your scenario fully :
  https://goo.gl/7OHDmn
• Sorry but I can't see that link .
• The website isn't available .
• are all the cats neutered?
• Yes, all cats are neutered . The female has always been timid and bullied . Once I fostered some kittens and when they started to run about even they ran after her and she was scared of them .
• A product like Feliway or Pet Remedy used as a plug-in both main sleeping/eating places upstairs and downstairs, possibly backed up with Zylkene for both cats to reduce anxiety (no prescription req) . I was watching Jackson Galaxy's show "My Cat from Hell" yesterday on Animal Planet or Youtube. He advised separating and then feeding the cats with a barrier inbetween and supervised, moving the food closer together overtime. This allowed the cats to sense, smell that the other was there but offered the victim some safety. The cats were never left together unsupervised. If you look on his website JacksonGalaxy.com it's got useful info. I foster cats for a small rescue and we always use the plugins and Zylkene for stressed, unhappy cats with great results.
• Thanks Clarabelle for your suggestion . He hasn't attacked her today but is looking for an opportunity . I feed him upstairs as I don't think they could be near each other to eat . He's never lived with another cat . He doesn't bother the other male cat . Will look at the plug in and Zylkene . Haven't heard of that before .
• Why don't you call a local cat rescue and explain the situation. They should be able to give you some advice on the best way to get all the cats living together in peace.