You guys already know about my poorly boy Rolo.. now my boy Scrat is very unwell as well. Scrat was the first ferret we ever chose and is a special boy to us, just after Rolo's legs went bad he started losing hair. We assumed it was from stress due to Rolo being taken from the group and recently adding a new ferret to the gang. His hair loss has become very severe and is symmetrical, leading myself and my vet to believe he is suffering from Adrenal - http://www.lbah.com/word/ferret-adrenal-disease/ WARNING LINK CONTAINS INTERNAL ORGAN PHOTOS, SURGICAL PROCEDURES. He is having ultrasound today to try and aid in the diagnosis, blood tests may be following if he can't find anything visible in the ultrasound.

Really not having a great time atm.

EDIT
After posting this literally just had call from vets - Scrat is very distressed and not co-operating at all with having conscious ultrasound so he's having to be fully put under now.

EDIT 2
Results are in - Scrat has a large cyst in one of his kidneys. Options are: biopsy under ultrasound (risky as near loads of blood vessels), removal of the kidney or just leaving it. Vet has recommended due to his age etc to just leave it as he feels the surgery would be tool high risk for him but if he starts showing signs of discomfort, behavioral changes etc to bring him back in to discuss it further.