Border terriers are cut from the same stock, I think. Ours will never complain if he's hurt, he just sort of muscles his way on through. Means you have to be careful, though, 'cause he can get hurt without you noticing.

The only time I ever saw him give a reaction anything like being in pain was when he sampled a hot pepper out of my mom's garden. He yelped, and I swear he jumped twice his height into the air away from the thing. :D