Possessive Aggressive Behavior - Urgent!

Question
I have a big problem with my 5+ year old GS. He was not neutered. On Sunday evening he attacked my miniature pinscher. The have been together always and are
best friends. Both male. the MP is neutered. But both are very possessive of me. The MP was badly bitten but is back home now. I sent the GS to be neutered
yesterday and is coming back home today. My question is: how do I integrate them together again? Should keep them separate for a while? Please any suggestion and
advise is greatly appreciated.

thanks,

maria

Answer
Neutering the GS was the right thing to do.  It is no cure all, and will take time for all the hormones to be worked out of his system.  How old is the Min Pin?  My daughter has a cross, and it can be quick to challenge Labs and Shepherds.  If it is still less than 3, it may have decided it was old enough to challenge the Shepherd.  

I would go ahead and allow them together as long as you can watch carefully and be ready to intervene.  Long term, you may need to give them better leadership yourself.  The key to most behavior problems is approaching things using the dog's natural instincts.  Dogs see all the people and dogs in the household as a pack with each having their own rank in the pack and a top dog.  Life is much easier if the 2 legged pack members outrank the 4 legged ones.  You can learn to play the role of top dog by reading some books or going to a good obedience class. A good obedience class or book is about you being top dog, not about rewarding standard commands with a treat. Start at http://www.dogsbestfriend.com/  For more on being top dog, see http://www.dogbreedinfo.com./topdogrules.htm