Guess your wife should have done a little more research. Yes, having a dog neutered does calm them down but that is when they are puppies. After they are a couple years old, the testosterone has already done it's deed and the dog will not be effected (calmed). I wish I could reassure you but from what I have researched, I can't do that. There are a few websites you can use by doing a google search but it may cause more insult to the action that is already done. Sorry!

 Yes ,in the long run it is a better thing that the dog was neutered.i have seen to many court cases where the dog escapes the yard or house and mates with the neighbors dog.the neighbor then claims losses do to not being able to the sell the pups for what they would have gotten for a pure bred pup. But i also understand wanting a pup from the dog you raised as part of the family....the big question, is your wife more important than the dog to you?.....hope this helps you get over this