Hi X, Yes it is the hormones (estrogens) that causes the swollen vulva, just like an intact female in heat. Quite often you will get a bacterial vaginal/vulva infection. Usually you see a mucoid discharge. Most of these do not progress to a bladder infection but that is possible. Usually keeping the vulva clean prevents further problems, but a topical antibiotic ointment (neosporin) and an oral antibiotic (amoxi drops, clavamox drops, or Baytril) may be necessary in some cases. Yes, melatonin may cause sleepiness during the first 7-10 days. After the ferret gets used to it the activity level increases again. You are not the only one who has trouble giving a tablet daily, that is why we are looking into the melatonin implants. Plus the constant release may work better than the once a day tablet. Good luck with Sassy, Jerry Murray, DVM [Posted in FML issue 3702]