The other side of the story, perhaps? I bought a dog from Battersea - he weighed as much as I did at the time. He was a lovely natured dog, but before I had got 100 yds along the street my legs were wrapped in the lead of a lady walking a very excitable yappy toy poodle who ran up to us. I was carrying an old fashioned type shopping basket which I clouted the poodle with. Its owner was shouting that I should have controlled MY dog.
No further problems on the bus, underground and main roads, even with lots of strangers petting without warning and even cats wandering around
Walking down my home street, a russell jumped his garden wall and flew at him, and ended up being lifted and shaken by this lovely patient dog. A peke did the same further down, and got a torn ear for its pains. Peke was unleashed and out on the footpath. Who was at fault? I got a lot of flack, and you might suppose that he was a dangerous dog, but he was minding his own business and behaving well until accosted.
As a dog owner for 40 years, I find that it is the Russells, cogis, Pekes, and toy poodles of the world who are often the aggressors - the problem is that, they are seldom killers because of their size, but any larger dog who retaliates can cause significant damage because of their size rather than their nature