JRT's rule!
Do you have a standard-size Jack or a puddin?
Our little guy's a puddin and can hold his own against our 80 pound lab-mix.
They're both 'real' dogs to me.
She is pretty much the standard size. Her mom was a short legged broken coat and her dad was a long legged smooth coat. She got the best of both, brown and white with nice straight long legs with a little bit of broken coat that really comes out when she gets her bath.
Even my husband who at one time said that any dog under 80 lbs was not a real dog agrees that there is no tougher breed in the world.