My family just bought a female English Mastiff. She is 4 1/2 months old. We also have an Austrailian Shepherd that we have had for 4 years. She and our Aussie are the same size right now. I noticed that the Mastiff has gotten almost territorial with our other dog...kind of growl barking and snapping at times. Is this something I should worry about for our other famiy members or is it just dogs being dogs and establishing boundaries?
