Revolution Dose for Fleas Only: 0.1cc of Adult cat Revolution (.75ml/45mg Selamectin) 0.1cc per 1.5lb 0.1cc per 0.680388555 kg (1.5lb) or Some ferrets are 1lb or less. If you need to protect against heartworms, and you only have one ferret, it has been suggested that you can use a whole dose of Kitten size Revolution to do so, not the cat size. Revolution Kitten tubes are .25ml and have 15mg of Revolution inside them. So, what Revolution says, is that 15mg of Revolution per animal under 5lbs, will be protected against heartworms (as far as felines). Buy the cat dose - the one for cats 5 to 15 lbs, and then do the syringe thing - pop the cap off one of the Revolutions, which are clear, and put the needle in there and suck up as much as you can, and inject it into the rubber top blood tube. The full size, adult vial for cats 5 to 15 lbs contains 45mg of Revolution. The vial is .75ml, and each ml contains 45mg, so 0.1ml contains 6mg. Get a baby scale, and weigh each ferret in lbs. The dose at 15mg per ferret, would be .25ml of solution per ferret. However, if you want to dose exactly according to weight, you can do that, too. We use 0.1ml per 1.5lb of ferret to control against fleas. Just do the conversion for each ferret after weighing in lbs. So if the ferret weighed 1 lb, just times 1lb by 0.1 and then divide by 1.5 to get .06ml of solution for a 1lb ferret. That ferret is getting 3.6mg of Revolution. This is a dose effective for getting rid of fleas, not heartworms. A 2lb ferret would be getting 8mg total. Remember - that was our flea only dose. I would recommend doubling it - just to be safe, to use the 15mg per month dose, if you are going for protection against heartworm. All of this is up to you - we don't use it to protect against heartworms, so our dose is much less just for fleas and earmites. If 15mg is sufficient to stop heartworms in other animals less than 5lbs, then I am assuming 15mg in a ferret is going to do the same, but again, I am not a vet. The dose I give for fleas, however, is MUCH less - so I'm not sure how safe it is to dose for heartworms every month at the 15mg dose. Some vets say it is still overkill. We won't know until there are actual studies done. However, it is obviously tolerated well since there have not been any issues that I have ever heard of -- and is better than having a ferret die of heartworm. If I had to worry about mosquitoes, I would dose at that level. [Posted in FML 7303]