[Roxanna]

Growling doesn't always equal aggression. Among themselves, the alpha dogs will correct the others with a growl to let them know they do not like whatever it is that the younger ones are doing. For those of us that have more than one dog, we see this all the time.

You should however, continue to supervise but do not separate them. Your dog needs to learn that even the smallest of humans is ABOVE him. He is the lowest member in your pack. Most Boxers are very protective of their human children and Duke will be too. In the meantime, just supervise their interaction.

Are you still exercising Duke daily? He might resent the baby if he feels he is being ignored since the baby's arrival. You could put baby in a stroller and you can all go out for a walk together. You'll be amazed how protective Duke will be of the baby out in public.

HTH