We were in a similar situation and I had read that getting a kitten of the opposite sex than the resident cat is best, so that the resident cat will accept it more easily. So we had an older female cat, and got a male kitten as her new companion. It took a good month or two of her hissing at the kitten, but soon they bonded and are now the best of friends. However, the older cat was territorial and neurotic to begin with. Also, the older cat did get annoyed a lot by how wild and energetic the kitten was. Over the years the kitten has mellowed out and they hang out together a lot.

I think if we were doing things over again we should have gotten 2 kitten litter mates as companions for the resident cat.

I think I'd you get a new cat, you should get a kitten. That way, the older cat won't feel as threatened. We've done that before. The original cat got a little hissy, but ended up getting over it. However, when we took care of our neighbors cat for a weekend, our cat was extremely viscous toward him.

I'm in tears now because you just reminded me of our beloved family cat who died suddenly almost exactly a year ago. We had two cats, who were almost 6 years old. I left my husband home to take care of the cats and went on a weekend outing with my kids and sister. One morning, he called me and told me that he found my cat, dead, in the kitchen. It was so sudden. There was absolutely nothing wrong with him. We still to his day dont know what happened, and are so scared to find our other cat the same way.

We had a similar pair of cats and one of them died. The remaining cat missed his friend for a while, but quickly got over it. He now is more affectionate with us. You don't necessarily need to get a second cat, unless you want one.

Introduce them slowly -- over a period of weeks

I'm really sorry for your loss. I have two kitties that are 3 years old. I think 3 years old is still young enough for the male cat to be open to a new friend. It's still a playful cat age, not sleeping ALL day. I would give it a few weeks tho- so that he won't tie his sister being gone with the new cat coming in.
I have heard that catnip all around helps the kitties bond in a mellow atmosphere.

Hugs!

We have had two cats for the last 4 years who were adopted together as kittens. Roughly 2 years ago we learned that one of the cats had a serious heart condition. Unfortunately, he died suddenly over the weekend. The other cat is healthy but I think she really misses her brother. They were very close and often slept and played together. My husband thinks we should get another cat so she has some companionship during the day when we're both at work. My concern is that cats often don't take to each other if they weren't raised together. It would be awful to bring home a new cat and have our existing cat get even more upset that she already is. I'm sure she would get over the initial stress of a new animal but I'm more afraid that the two might not get along in the long run, which would defeat the entire purpose of getting another cat. What would you do?