I have to separate pairs of ferrets - two (Nito and Nymphadora) that I had living together for about a year before I got the other two, and two who are siblings that I adopted together (Dot and Ozzie). Shortly after I adopted Dot and Ozzie, Nymphadora got very sick and was diagnosed with insulinoma. I put off even trying to integrate until I got Nymphadora back in good shape. 

Now I'm ready to try again, but it's really hard. Nito and Dot get along ok; I haven't had them together much but they don't fight when I do. Nymphadora and Ozzie both LOVE to fight in general. Nymphadora is very tiny and is the oldest; Ozzie is younger and a male. Whenever they can get to each other, they fight pretty bad. The other day Ozzie got out when I wasn't paying attention and he got into with Nymphadora and cut her back. The skin was broken, but it was very shallow so it didn't really bleed (no blood actually running or anything). When Nymphadora gets into a fight she shrieks and it freaks everyone out (she does it when she's winning too). After this incident I noticed that Nito (who wasn't involved) was much more skittish than usual. Anyway, I could use some advice. They have been living in the same FN 182 for several months (I just blocked it off so it's two separate compartments). So they're pretty accustomed to each other's scent. I make sure to switch their litterboxes, blankets, food dishes, etc. to discourage them thinking they own it or whatever. I know that my mom has tried the old "bathe them together" trick and it didn't seem to help.


I am also pretty sure that Ozzie would attack Nito and Nymphadora would attack Dot if she had the chance. I was told by the SPCA that Ozzie had attacked another ferret that had attacked Dot. I don't want to give up yet though.

All I can say is it depends...  Depends on how much you can stand while they sort it out.  I've thrown pairs together with no problems, and I've got singles recently that took months to get along.  Usually it's the girls that were the worst, but Yoshi had problems with Rosa and Lola.

Years ago, I was introducing new rescues within a couple months of the last pair of rescues.  They didn't have problems.  Bt the last few times we brought new ones in, the existing crew had been together for at least a couple years.  Territories and pecking orders established.  Toss in an younger one and the fur flew.  

THE DOOKS OF HAZARD