boxers getting them back together

Question
I have two boxers white one 15 months and black and white one 12 months who got along wonderful until about three weeks ago the white one became agressive i have recently had them neurtered and now i would like to get them back together as before - best buds.  they have been separated since them and are also going to obidence classes.  don't want to have to get rid of one of them for they are my kids and i just put one asleep in july.  please help. will they ever get along.  i also have a female in the house who is 11 yres old and fixed

Answer
Hi Nancy...

The only advice I can give you based on what you've said is that your 15 month old is going into doggie puberty and may act like he has a screw loose for a couple months but should get back to normal.

A couple questions...

There is no such thing as a black and white Boxer.  Boxers do not carry the gene for black coloration.  Are you positive he is a full-bred Boxer?

Where were these dogs purchased?  How long have you had them?  How long have they lived together?  Were there parents health and temperament tested prior to mating?

Can you please be more specific?  "The white one became aggressive" isn't telling me enough for me to be able to help you out.

What type of aggression was displayed?  What were the circumstances?  How was the aggression stopped?  Were there injuries?  Please be as specific and detailed as you can.

Are they able to see each other even though they are separated?  

What were the circumstances surrounding the euthanasia of your dog in July?  What type/sex/age was this dog?

You say you have a female in the house?  I assume you mean another dog?  What breed?  What is her normal activity level/interaction with the other 2?

Have you discussed this problem with your trainer?  Have you tried anything other than separating (that either did or didn't work)?

The more information you provide, the better I can assist you.