The original Labrador gradually died out in Newfoundland on account of a heavy dog tax which, with the English quarantine law, practically stopped the importation of the dogs into England. (akc.org)
«Richard Benyon MP: British servicemen overseas must not be disenfranchised at the general election Main Nick Herbert MP: What the Government's dog tax debacle tells us about this Labour administration» (conservativehome.blogs.com)
Proof of the dog's occupation was a docked tail, which made him exempt from the English dog tax as a working dog. (oldenglishsheepdogclubofamerica.org)