how to keep my dog from killing others

helloo, I just started playing Minecraft so im sorry if i get any terminology wrong...but I was wondering how (or if) I can prevent a certain situation from happening.

I have a tamed wolf in a server with my friend...but every time my friend successfully tames a wolf of their own, my dog attacks the new dog and kills it unprovoked. Is there a way I can prevent this because their new dog has died like 3 times :(((