Should I separate them?

Question
QUESTION: I have 3 male ferrets who were all gotten at different times. They live in a FN142 with lots of things to do when I am not home to let them out.

They have lived together almost 2 years my oldest is 5 years old my youngest just turned 2 and my middle guy is 3 years old. It was a breeze to get them to get along.

But now my middle guy seems to be getting picked on by the youngest but he is best buds with the oldest. I noticed him losing all of the hair on his tail so took him to the vet who told me it was some kind of stress at home after he ran a ton of tests. But I didn't know he was being picked on at the time so I set up a camera and the younger guy basically drags him all over the cage by the neck and fights him when he tries to eat.

So I guess my question is if I separate him from the other 2 will it stress him further since he is very close the my older guy. But so is the younger one. I am not sure how to split them up since both love playing with my older guy.

ANSWER: You could always try to separate them (and rotate them so that the oldest and youngest can still see each other).  But, I would question the stress diagnosis.  At age 3 with hair loss, adrenal disease is a real possibility.  It would explain the hair loss and possibly why he is suddenly being picked-on.

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QUESTION: He has been tested twice already by 2 different vets for adrenal disease in the last month as that was my first thought as well. He has another vet appt. for his shots in a week and I will probably have him tested again by his regular vet.

I guess my question is would rotating my oldest guy stress him out? Even though it will still technically be the same cage he is used to just separated.

Answer
If the hair loss is all-over the adrenal is a possibility.  If the hair loss is up by the neck, then the other ferrets teeth could be causing it.  While it would be unusual, the younger ferret causing the trouble could have medical issues!  Part of me says that if the ferret isn't showing signs of stress (other than hair loss) then it might be worth while watching them for alittle while before separating them.  I imagine something will stress one of the ferrets out, but rotating cages may be the least stressful if the ferret being picked on is over-stressed.