Wondering if anyone can speak from personal experience of the following and the results. Currently four ferrets, 3 females and 1 male and the male has been vasectomised so his main purpose is bringing the females out of season (I understand I can simply get them jabbed but this is my prefered way of having them and will not be changing). Currently all four have the run of about half the house and they are never seperated, and for 3 years this has worked just fine. Took in a male a couple of days ago as a temporary home to see if his owners could be found, and if not then the possibility of keeping him is there. He seems to have no issues and looks healthy enough, in addition he has been castrated at some point in the past. I am well aware of the dangers of keeping males together during the breeding season, but not too sure how it would work with a combination of intact and neutered males. I would imagine there will be the usual aggression to begin with to establish the dominance order, but what then? Will my own male be likely to constantly see this new male as a threat when in season even though the new male will not be giving off any of the typical in season signals. Or will he be treated more like an adolescent male or even just ignored totally? Has anyone ever kept males together when there has been a combination of both intact and neutered males, and if so what was the general outcome?

I had two boys that were whole.  They were brothers.  I didn't have any problems with them.  I have also had a whole hob with the others that were spayed or neutered.  Never, so any aggression between the ferrets.  

When my whole hob came into season...he would be just a pain in the butt....if you know what I mean.  I just separated him from the others until he came out of season.  I would just take it day by day and see what behavior will come out when he is in season.  Then deal with it when the time comes.

Good luck.