When we first looked into adding a dog to our family, the first question was always whether the dog liked cats. When Girly (sable colored sheltie to the far right of the photo below) was featured on the rescue site, we were told she was tolerant of the three cats in her current home. And that trend continued when she came to us ...tolerant of three cats. As it happens, we had four cats to introduce to her and she was fine with 3 out of 4. The fourth, Sebastian, gave his thoughts of having a new dog in the family (hiss, growl) and now these two have a wary truce in most cases unless they get in close proximity.
The merle sheltie you see above came to us through the rescue about 3 months ago. She is 12 years old, has poor eye sight and is arthritic (also had to have 14 teeth pulled). She has also encountered Mojo before (one of the three grey cats living with the wonderful woman who runs the sheltie rescue) and as you can see, has a fascination with cats. She always has an eye on any of our cats who walk by her in the house here and yesterday, she was the only sheltie at the picnic who had an interest in a close up cat view.
The rest of the shelties simply saw Mojo as just another four legged furry running around the backyard.