Well over ten years ago I bred Saint Bernards. Beautiful dogs, I took it very very seriously, trying to 'improve the breed', much research putting certain bitches with studs etc etc. It was my 'job' for a while. There is a lot of science in it and care (and money). It went really well for years, it was a joy to see how happy people were with their puppies, and as a family it was lovely. And then it wasn't. Nelson came along from another breeder as a stud and he was the sweetest, most gentle, docile, timid puppy we had ever had. He was utterly adorable. Blood lines were absolutely excellent - on paper was top notch and we paid an absolute fortune for him. He was extremely needy and sweet right from the get-go. Cut to him as an adult at 2, and he was 100kg, completely docile (too much really), and absolutely adored us - a family with 4 young kids. HOWEVER, once he hit 2, to him the world was a scary place and people were out to hurt his family. He started to snarl, and would lunge and try to attack anyone that came near during walks (EVERYONE wanted to pat the huge st bernard but they just couldn't). Then I couldnt walk him cos he weighed more than me...and that made things worse. Then my kids couldnt have playdates because even though id lock him in the garage Id be terrified of a mistake. We paid thousands on a behaviouralist, but nothing worked. We had to accept we had a lion in the house who was obsessed with us and wouldnt hurt us but would literally rip apart anyone he viewed as a threat to us. It was terrifying. For that period of a year it ruined our social life as I wouldnt have anyone to visit due to sheer worry about what would happen. He never actually hurt anyone, but on walks he sure looked like he would...
The turning point was my sons friend knocked on the door unannounced and Nelson went beserk - up on his hind legs going mental at the door - to a 9 year old!!! If that door had been open I absolutely dread to think what could have happened. That was the end for us. We did surrender him to the behaviouralist in the end who felt we needed to give up (after paying thousands) and he took him on as a project. This is so many years ago now, but that was the catalyst for us that we ended breeding. My view before that and after are very very different. I believed in its not the dog its the owner and breeding. I now think its completely and utterly random. No dogs should exist that can overpower a child (not an adult - a child - cos you never ever know). Its like having a lion in your home and you would never do that, and then blame the owner/child when they do what comes natural. I see these idiots who have actual lions as 'pets' on the internet, and yes they can connect and be lovely and gentle - but they can snap at any time. Same with bullies and any large dogs. Literally any time they can snap and there is bugger all we can do about it.
Its hard because I know the joy dogs bring, but from the other side as what many would consider a responsible reputable breeder, I call BS on a lot of that. A puppy can have the best bloodlines in the world, and the most dedicated owners, and training and environment - AND a breed that is renowned for being 'gentle' - and still it goes balls up.
IMHO bullies should without doubt be culled and banned and it should have been done ages ago. BUT I think we need to go further. There are many dangerous dogs living with and being around children that simply shouldnt be. Families think 'my dog is so gentle' but he may be with you guys cos you are his/her pack but he may be the opposite with others. He may some day even turn on you. Im a social worker and I wont go to homes with large dogs for this very reason. I dont care what they say about them being lovely - any dog that can overpower me is unsafe, end of. They originate from wolves and unless they are small and manageable they shouldnt be pets. Controversial I know...but I dont think Im wrong. I may be accused of being a hypocrite because I am - at one point I had 4 adult St Bernards living with me with 4 kids - but now I know better. I cringe that I did that tbh. No child or adult should ever die or be harmed by a pet. Its just wrong full stop.