In response to Greg's question abouth his thin 1 1/2 yr old sprite. Iams kitten food is a good quality food for your ferret, however if she has lost some weight after her vaccinations -- this is not uncommon due to the reactions of the culture on the immune system which can cause lavck of appetite to ferrets (and humans) ... Unless your vet feels there is a valid health condition you could ask about supplimenting your ferrets regular diet with Nutri-Cal or NutriStat . This is available through your vet and is a vitamin suppliment for cats and dogs, but has worked well in stimulating appetite and putting weight on underweight ferrets which come into the shelter here. We suppliment the ferrets diet ( after determining if it is strictly a weight problem) with about 3/4 - 1 inch of Nutri-Cal daily. In two to three weeks you should see a difference and then can wean them off it. [Posted in FML issue 1455]