http://www.smartgroups.com/message/readmessage.cfm? gid=1423922&messageid=10138&startid=10141 Good question. Yes, intact male ferrets during the breeding season will have hair loss and have an increased musky odor, and sexual behavior Sometimes they will have aggressive behavior too. Sounds like adrenal gland signs because these signs are caused by the same sex hormones! No, I do not think there is any testicle left behind when they neuter these boys at 4-6 weeks of age. Neutering is a very simple surgery to do, but anal gland removal can be a hard surgery to do. Thus it is not surprise out of the hundreds of thousands of ferrets a few will have problems from the anal gland surgery. Thus if your young, neutered, male ferret has a thin hair coat (especially on the tail) this may actually be an early sign of adrenal gland disease, despite the young age. Hope that helps, Jerry Murray, DVM [Posted in FML issue 4610]