I agree with everyone, so basically it all depends on the dogs personality, how they are raised & treated. I've known many JRT that get along great with smaller animals & I also know many that don't. And it varies too, I've known some JRT's that have never seen a cat before & even as an adult get along great with them, then I've seen puppies raised with kitties that don't get along. I've known JRT's to get along with cats for years then all of a sudden not & vice-versa. I guess you never know until the time comes.

To be on the safe side I'd probably stay away from that breed unless you are prepared to seperate them (possibly for life) if needed.

Don't get me wrong they are a great breed, just not for everyone.