Introducing Dog Number Two

Question
Recently my fiance and I bought a puppy (3 months) for our other puppy (9 months.)  Our first dog is the sweetest, kindest dog ever and dog number two is just not as easy going.  Most of the same they seem to get along, but more and more I hear growling.  Many times the growling occurs when we first come home, but many other times as well.  How can I determine if they are playing or fighting?  If they are fighting, is it too late to have them be BFFs?  Thanks!

Answer
At this age it is difficult to explain, as the 3 month old is emulating "fight" behavior in its play.  The 9 month old is at a point where it is getting adult drives and could be playing or could be acting dog aggressive.  Much will depend on the breeds and original temperament of the dogs.  Your best opportunity would be to take advantage of a play session in your area led by a trainer/behaviorist, or find one that will evaluate your dogs while in a play session at your home.

It is not unusual for dogs to fight at this age if not guided into appropriate levels of play.  I would love to be of more help, but without seeing the behaviors of the dogs I would not be honest in telling you a definitive yes or no.