James, ferrets are used for developing effective influenza vaccines. There actually are and have been people on the FML who adopted such ferrets afterwards, though I don't know if that is still going on. (I sure hope that it is.) I don't know what other things they are used for in relation to health (not colds because it was found that they don't get those) but looking at Fox's _Biology and Diseases of the Ferret_ may give you a range, ditto sites on zoonoses such as http://research.ucsb.edu/connect/pro/disease.html#b7 You are right that the individuals used need to be healthy, with rare exceptions. I can recall a time many years ago when there was an offer to adopt and care for ferrets with lympho from a research facility which was studying the various forms; we were among those asked but Steve and I chose to care for her ourselves at home. Yes, ferrets have been used to improve health choices for ferrets. Steve and I were around from the beginning when the ferret community was first trying to reduce the public tendency to freak about ferrets in relation to rabies (a process that took about 10 years from start to finish with breaks between some segments). The first step for that was to find out which rabies vaccine they tolerated. That work actually was done at Marshall Farms and largely done at their expense, with Dr. Judi Bell involved. When it turned out that one vaccine had bad health reactions Judi adopted those few individuals, who thereafter lived normal pet lives and one actually went on to live an unusually long life. Then the next step was that the USDA had to find out which ones worked in ferrets and which of those worked for at least a year (They have not been tested for over a year, but one worked for only 6 months and was dropped for consideration for that reason.) Later the funding was gotten together for the CDC to study two rabies aspects in one series of studies in conjunction with the U. of Kansas and U. of Georgia. The two things under study were: how much do the common U.S. strains of rabies differ in one species, and how safe are ferret in relation to rabies. Those particular studies did involve ferrets dying but within a few months of their conclusion more ferrets were saved by changes to the Compendium of Animal Rabies Prevention and Control than had been lost to the studies, an effect that was greatly helped by the efforts to get that change information out to state and local health officials and emergency room personnel all over the nation, something which it makes sense for people to continue doing using the info at http://www.avma.org/pubhlth/rabcont.asp (The Compendium of Animal Rabies Control) http://www.cdc.gov/ncidod/dvrd/rabies/Ques&Ans/q&a.htm (Easy to read rabies Q&A from the CDC) For those curious about why shavings are inappropriate: http://www.trifl.org/cedar.html (epidemiological cedar and pine info) [Posted in FML issue 4179]