Thanks for your thoughts, I do see the markings of a Jack Russell so I never questioned that, the person I got her from seemed to think she was too but obviously something was going on. My vet thinks she looks more staffie like, everyone can see something different, she does look staffie to me but I always come back to the thought of if she has got Jack Russell in her then the size difference of the dogs is weird. I suppose I'll need to get a dna test if they are true