So my in-laws have two dogs, Memphis and Jack. They used to have 5 dogs, but they've rehomed the other three, one by one, because Jack would fight with them. They didn't rehome Jack, bc he was their first dog. He's only 2-3 years old. He was fine with Memphis. But now, he keeps fighting with her for no apparent reason. My mother in law actually got a pretty nasty bite from him, when she tried to break up a fight and he accidentally got her instead. They were going to rehome Jack, but the other day, he growled at my sister in law, again for no apparent reason. So they're thinking of putting him to sleep. Is there anything they can do? I love this dog. He's a great dog. Is there anything you can do, like medication or anything to get rid of aggression in a dog? He's a karelian bear dog, if that helps at all. Thanks so much!