We have two male Siamese rescues. Hershey is our 4-year old who\'s been with us for two years. Our previous second cat suddenly died at home (stroke my M.D. spouse diagnosed; was 15 years old) before the holidays -- Hershey seemed distraught when it happened -- and we went and got a new companion cat, Snickers, who\'s about 1 year old (much smaller than Hershey).
Snickers is highly affectionate and so far has no fear of Hershey. However, Hershey rejected the idea of a new cat from the start (he was rescued from a 200+ cat hoarding and has always been around other cats). We kept Snickers in a separate room the first week, and Hershey seemed to pay no attention -- no paws under the doors, and when we would take Hershey into the room he would simply sit in one place and growl. Since New Year\'s we\'ve given Snickers partial to full run of the condo; when he\'s loose Hershey retreats into hiding places -- for the past two weeks our cat condo tower. Typically he\'s been staying ithere all day, and seems to come out only in the middle of the night to eat or use the litterbox. I can remove him from the condo and place him on our bed or inside his cat bed on our sofa or kitchen island to be part of the action -- he\'ll stay there without moving, and will growl/hiss at Snickers whenever he comes to sniff or check out Hershey. There\'s at most one screaming cat fight per day that never lasts more than five seconds, and it usually happens so fast that I seldom see which cat attacks first. (Hershey has his claws, Snickers came to us declawed, but we haven\'t seen any blood or injuries to worry about.)
When I\'ve tried locking Snickers in a separate room for the evening (with food and litterbox), Hershey may or may not come out to sleep with us. If I keep Snickers in a room by himself during the day, Hershey will eventually come out from the condo and act like his old self to a point.
It is totally unlike Hershey to be so fearful/territorial. I suppose we can go back to keeping Snickers in a separate room once again but I think Hershey will again totally ignore that room.
The rescue organization -- and my vet -- have suggested this is typical Siamese behavior and I should give it more time. I thought opening this to some outside opinions might help. Thanks!