My two cents on the flea problem: I can't imagine why anyone would still be subjecting animals to flea powders of any kind. The mess, the uneven distribution, the inhaling, not to mention what happens when the animal gets wet, or the relatively high toxicity of carbamates or even pyrethrins. Using flea powder today is like using a candle to light your house, or cooking on a woodburning stove. (Although I guess there are people who actually enjoy those things). Advantage and Frontline are both safe and effective for ferrets. We've dispense thousands of doses, and the only side effect is occasional irritation of the skin where it's applied. As for the cost, here's a tip: Advantage, for example, is all the same concentration. The only difference is the amount of liquid in the tube. A small cat dose is 0.4 ml, where a large dog dose is 4 ml. A ferret needs 0.2 ml. How many ferrets can you treat with one large dog dose? You do the math! :). Dr. K. [Posted in FML issue 2388]