How can I make my older cat more comfortable?
I have three cats currently. I started with two (brothers that I got at the same time) and have had these two (Thor and Loki) for almost 5 years.
We introduced a new kitten (found by a friend) about two months ago. For the first two weeks, the kitten (Balder) was kept in his own room without access to the other cats.
After two weeks, I put up three baby gates so Thor and Loki could see/touch Balder. This lasted for at least another two weeks, if not longer.
Once Thor and Loki seemed comfortable (Loki took the longest), I let Balder out of the room to interact. They all three play and cuddle and things seemed largely fine.
Thor, however, now seems depressed and on edge. Balder annoys him because he is so playful. Thor still eats as long as we stand guard and don't allow Balder near him (otherwise he just gives up and walks away).
He will still come cuddle in bed so long as Balder doesn't mess with him. His personality towards us or Loki hasn't changed, but he will definitely seek more places to hide than he used to and sometimes we won't see him all day.
I am very worried for him. Balder has been "integrated" for about a month and a half now and I am concerned this isn't going to change. Is there anything I can do to help ease Thor's stress level and make his life more comfortable?