well I don't know. I have multiple dogs and never have problems with that. But our neighbour has two malinois and they are like that. When they see a strange dog or human they come to the fence and than one dog attacks the other (always he same dog starts the fight) and than they fight. Which is kinda of stupif if you ask me, cause if they fight each other they are not efficient at keeping the intruders away now, are they..? Perhaps it is really to do with the dominance status, but also I think the dogs temperament. I know malinois are very reactive...Which LGD do you have (breed)? is that the actual footage of your dog or just an example of the behaviour (neo dog) ?