I adopted what I thought was mostly a male black lab two years ago. I am starting to wonder if he has some pit bull or rott in him. He is very sweet and devoted to my human family. We have to watch when we play with his though because he is about 100 pounds, and he plays very rough. The sweetness of this dog kinda disappears around other animals. When he was introduced to the ancient Brittany Spaniel female next door, he leveled her. She fell to the ground before we could get our dog off her. He pulled me to the ground to attack a female pit bull dog tied to her own fence. He also knocked a twelve week old puppy to the ground at obedience school. He is hard to handle around other dogs, like at the vet. I walk him on a pronged collar just so I can handle him. I am trying to understand his behavior. He is very confident, but he isn't aggressive at all to humans. I can take food out of his mouth, administer medications, and he will let any people in the yard or house. Is it normal for some males to be so aggressive toward other dogs, even puppies and elderly dogs of the opposite sex? I am also wondering if I hadn't stopped him, what is his goal with these dogs? Is he trying to kill them or just overpower them?
To me it sounds like he wasn't well socialized around other animals and no, aggression is never normal. It's good he doesn't show any aggression to people but his reaction to other dogs definitely needs to be corrected. Have you tried this method?


Start socializing him around other dogs. You'll ideally need someone to help you, someone with a dog whose personality is balanced and non-combative, who you can work with together. You'll need to meet this other dog as often as possible and always correct aggression with redirecting your dog's attention like it's shown in the video. Obviously you'll need loads of patience and confidence (more confidence than he's got!).

It's difficult to say if he's about to kill them, perhaps he simply doesn't know how to behave around them or he had a bad incident with another dog in the past so he hasn't learned to trust other animals. I can't really tell knowing nothing about his background.
Thank you so much for the response. I watched the video and it makes sense that he just may not have had proper socialization as a pup. I am a little nervous about socializing him, but I think in the long run it would be good for him. He would get to do so many more fun things if he knew how to behave around other dogs (going to parks, riding in our boat, going out for ice cream, etc).
Anonymous I am a little nervous about socializing him
You really shouldn't be because he'll sense your inner uncertainty and this will make the process harder and longer. He'll have to deal with both your and his own anxiety if you see what I mean. If you don't think you can manage him, how about hiring a dog behaviorist?