Jim Dandy: Hi, I had two females cats, both were rescues which I had had for years. I decided to have a dog rescue exactly the same as youre thinking of doing now, & had the exact same concerns & worries you have too as my cats were both so happy.

Well a dog came along, hes was a rough collie (like lassie only black & white) I brought him home on trial for a week to see if he would get on with my cats. I thought if it doesnt work I just simply cant have him as I didnt want to upset my cats who had been through alot previously. I desperately hoped all would be well though. Anyway, the first day or so there was alot of hissing and bushy tails from my cats & he was scared of them! He was such a big laid back dog, had been badly neglected & was in a very bad state...it took a few months  to get him  back in shape. He had previously lived with a cat aswell.

Thankfully they all eventually got on a treat & it was a happy family. My one cat used to snuggle up next to him!

I think the main points that really helped us, that have been mentioned in previous posts, were:
1 He was older & very laid back not boisterous in the house
2 He had lived with a cat before
3 The cats were there first

Hope this helps a little :o)