As you can see above Moby is enjoying the new Colossal rope we've got but even Merlin, Abbey and Eigg - who are all shorter than it - enjoy it! But keep in mind that toys should be taken away when the play has ended and they should be used as treats. We have a certain chocolate Labrador who likes to bust up our toys much to our displeasure.
Secondly - though the most important of all - dogs should know their family and their position in it. Either in a single dog or multiple dog household, there should and must be a hierarchy in which the dog(s) are at the bottom of it - even below other family pets! Dogs are natural to pack leadership, the owner must always be and act as a leader. Dogs who believe they are the pack leader will become troublesome and possibly aggressive to other canines.
As you can see from these photos there is a general feeling of who's the top dog: Abbey is showing her dominance to the rather posing Eigg and Starsky is showing his by checking on Hutch who constantly looks up to his brother.
Once a dog knows their place, there will be times when they will challenge either the owner or other dogs in the house for dominance - this is natural of pack animals. Always remember to show them that you are the boss and harmony will return.