Thanks to Jonny for this. He says:
"it's from a pittsburgh sports bar in ocean city maryland called buxy's salty dog saloon. it's a steelers/penguins/pirates fan's paradise. they have a whole bunch of ridiculously awesome shirts like the one i have. once i saw this one on the cute waitress that was serving me, i was like i have to get it. i took a bunch of photos so enjoy man."
This establishment took the "Dog" part of their name and really ran with the Pens angle. You got the classic Mike Lange quote at the bottom, and all the semi-recent Pens stars are recreated in anthropomorphic dog-form. Dog-Sid and Dog-Geno are probably injured at the vet somewhere, Dog-MAF and Dog-Staalsy are doing everything they can right now to keep the doghouse from collapsing and Dog-Gonch was sent away to some farm to run free in the fields.
Check out closeup pics of the individual player dogs below. Click to view them close-up.
(thanks to Cotter for the banner pic)