Yep a Jack Russell does not know it's own size, got one staring at me just now trying to convince me it is lunch time and that he needs fed...
He has not got too long left in him, he is 17 now, almost blind and totally deaf but he is still very active. I thought he was going to leave us a few months ago, but I changed his diet to boiled fish and rice and that has given him a new lease of life, he is much more active and has regained the weight that he lost when feeding him commercial dog food.
Tough little dogs those JRs,