Ditch-jockey has it right, those with the dogs already flout the laws that the rest of the normal population follow, it won't make a difference.
FWIW many pet health insurance schemes already include liability cover, ours does, but only if the dog has never been reported or complained about. Also not cheap, currently paying about £20/month, which is almost the same as the insurance on our 1.4 diesel Ford Fiesta.
