I have an older dog who keeps trying to fight with my younger dog anything I

[Shalom]

could do to stop this? When I first got the puppy he was 2months old he is pitt mixed. My older female dog is a full pitt. At first they got along great and a few months later the female one day attacked him for no reason after that we kept them separated for a while and would let them sniff each other both being held on a leash and then she jumped at him to bite him again people are saying that it could be she is jealous but we showed her as much love as we do to the puppy. We love both of these dogs deeply and want to keep them both. Is there anything we can do to stop the female from trying to bite him