I have but since the fleas were back just a week or so later I switched
dog, cats and ferrets to Advantage II.

Note that whether it's Kitten/Small Cat, Small Dog, Medium Dog, Large
Dog, etc it's all the exact same product in the tubes. Just the amount
in the tubes varies. So you can save a LOT of money by buying the
biggest dog dose and then using a syringe to dispense out the
appropriate dose based on weight. Your average 2lb ferret only
needs .1ml (note that's POINT 1). Cats need .8ml. Here's a chart
http://www.lisaviolet.com/cathouse/advantage html
I also order it via 800petmeds.com and Google "800petmeds.com coupon
code" and usually find a $5 or so off coupon.

I also only dose my ferrets that first sign of infestation - not all
the time. My new place I moved into ended up with fleas due to a
neighbour with roaming cats she didn't bother treating. So everyone
got dosed then after that first dose just the dog and cats then after
that just the dog since he's the only one that goes outside.

Note, too, that if you have other pets you are dosing unless fleas are
really plentiful you can forego the medication on them. It's pretty
easy to use a flea comb and catch any random fleas on a ferret and
also wash their bedding thoroughly in hot water.

[Posted in FML 7806]