for those saying there should be a dog license how would it work to actually stop anything?
Mandatory training classes for every owner, licence and registration of ownership for every dog, all dogs must display a 'licence tag' along with the regular one and the microchipping or be taken off the owner there and then, proper punishments for owners failing to meet their responsibilities... Be nice to have the RSPCA get some proper powers of enforcement, too, which would make an impact in poorly treated dogs that end up turning nasty.
Labradors are the most dangerous dogs in the uk on the number of biting attacks iirc.
And yet also the most common breed for nice, calm Guide Dogs... which, IMO, is more evidence of nurture over nature.
There's your mistake, You should have gotten a giant otter, those things would tear most dogs apart!
OMG yes, I *LOVE* otters!!!
Can I have one, please? Can I, can I, can I?

One of the keepers down at the Tamar sanctuary spoke of how a fellow keeper lost his footing once during feeding time and got savaged by a swarm of the little ones - Apparently even one European otter is a challenge, which is why they needed a whole pack of hounds to hunt them.
Colour coded mandatory collars for dogs deemed potentially dangerous so people know when to give a wide berth if they have children or a dog which is easily agitated
There already are black & yellow coats and even ribbon-leads, that warn people in BIG lettering to keep their distance from the dog...