Sort of. As I've mentioned here, my "new" dog Loki (a black lab/ pit mix) was slated for euthanasia due to aggressive behavior at the pound. He's good with women and children. Even cats. He's not good with men or other dogs. That in mind, I don't take him out. Ever. 

However, one day within a month or two of bringing him home, we were carrying groceries in through the front door and my neighbor's dog came over to say "Hello." Their dog is older and super sweet... I think a golden retriever... and I've known the family for 20 years. They're good people and we've collaborated on neighborhood projects but we're not "friends." 

As luck would have it, as soon as Neighbor Dog (ND) made his way over to our yard, my youngest son popped the front door open and Loki came barrelling out. I was mortified. Within seconds, Loki was on that dog and snarling. He pinned ND down and wrapped his teeth around ND's neck. I'm sure I let out a bloodcurdling scream that could have been heard for miles and began screaming at Loki. Getting in the middle of those things can be risky- I wasn't sure if Loki would rip my arm off and keep going for the dog or what, but as I screamed Loki's name, he paused and looked up at me for a moment, then backed away a bit. I grabbed him and lugged him back into the house. 

Thankfully, ND was totally unharmed. Loki apparently wasn't trying to hurt him. If he had been, I have no doubt he could have torn the other dog apart. He also stopped when I yelled at him which caught me by surprise. My neighbor accepted the blame for it as well, saying their dog shouldn't have been out without a leash. ND was initially in my yard even though the mele happened in the street. Either way, I consider myself lucky on many fronts. If Loki had hurt ND, I probably would have had no choice but to put him to sleep. About a year has passed since the incident and Loki is doing better but I don't think he'll ever be the type of dog I can take out without worry.

I am not really a d*g person but have almost always had a d*g.

I mentioned my golden retriever, he got attacked when he was young and didn't like other dogs after that.. My next dog, a Rottweiler, loved other dogs, but one day she went over to play with another dog, no aggression and she was only a puppy at the time but the man accused her of attacking and a passerby, a man, said he'd confirm that my dog attacked the other guy's dog. I took my dog home and went back to find the man.. I found the man who said he'd confirm - and I asked him why he said that... turns out he knew the dog owner so they were in collaboration. Scared the living daylights out of me as a new Rottweiler owner as I'd heard that a Rott only has to be accused of aggression and they get PTS... so I never let her off the lead again..  She was a great dog, I'd walk her to school with my young kids.. she always behaved impeccably and never batted an eyelid when other dogs, or their owners were aggressive 

As a kid, I did have a dog, Lucky - he was ok.. unless it was a dog that was bigger than him, smaller than him.. black or certain breeds - he would try to attack dogs a lot..  

We had a long haired doxie.  She was a very nice dog.  She was dachshund so she did bark a lot (Though we did get her trained to be quieter)  She played with our kids, cats etc.  But we lived in an apartment and the people upstairs had a dog. Our doors were about 5 feet from each other.  Once we happened to both come out of our doors at the same time.  And she ran over to the dog like she was going to attack this dog 3 times her size.  I pulled her back and they pulled their dog back (both were on their leashes but as I said our doors are right next to each other)    Afterwards, I checked to see if everything was okay.  Their dog was not hurt.  I was pretty sure of that but was very sorry about scaring their baby.  So we made a point to be much more cautious as we went out the door from then on.