I choose not to expose my dogs to other dogs. I have 3 dogs, all different. The largest is the best behaved and has never been agressive but because of his size and breed he can be scary to other dogs. Humans are just as nervous. He would never hurt another dog or person unless he knocks them down when playing.
The second is the trouble maker, he will tend to try to prove to others he is in charge. He does not like strangers in the house so he has to be put behind a baby gate. He will nip at the plumbers ankle if he gets the chance, so, no, he does not get get the chance. Oddly enough, he seems to accept and understand a normal visitor. He may bark at first, then this person is a friend he settles right down.
The third, the smallest, will throw a fit if a stranger comes in. She likes to think she is tough, can put on quite the show but wil lrun off, hide under the bed. She has no desire to bite or fight. She just reacts with barking as a defense to a preceivd danger even if it does not exist
The first dog came to me after his owner passed. I knew the dog well and he had stayed with me before, knew the dogs in my home. The trouble maker was from a rescue so I did not know his background. The third, I got from the local city shelter, she was born there, had no trauma but once she came home she was rarely left alone. Even now, when she sees me getting dressed and putting on my shoes, she knows I am going out, runs to the bedroom and puts herself safely under the covers. When I return, it maybe 15 minutes or 2 hours but I am treated like a movie star, she is so happy I have returned. She has been here 11 years, she knows I will come back so I do not know why she worries when I leave.
It is the responsiblity of the owner to know their animals, to take proper care and to limit or avoid any situation that could get them hurt or put anyone in danger.