My first thought was to tell you I would be afraid to try it because the animals are not young. It is easier to have a smooth transition when you are dealing with puppies or kittens. That said, it looks like the others who have commented have had good success so it may just work out! The idea of bringing a towel with the dog's smell back to the cats was a terrific one. My two cats had lived with dogs before but it had been two years since the last dog died. We decided to get a puppy so that she could grow up with the cats. In my case it has worked out beautifully. There really are no problems now but I did watch them VERY carefully in the beginning. I'd say go and try it and good luck!