I am glad to see a lot of good advice going out on heartworm disease in
ferrets.  With the flooding here in Wisconsin we have the largest number
of mosquitos that I have ever seen, and I am really pushing heartworm
prevention to all ferrets, indoors and out.  My only word of caution is
for those of you mixing up your own "heartworm prevention".  Ivermectin is
a very touchy medication and once mixed should be protected from light (a
dark colored bottle).  Also I prefer the fresher the better, so mix fresh
every year, or sooner.  Watch the dates on the bottles of Cattle
ivermectin, it won't last you more than a few years.  It's no use trying to
prevent with a drug that's lost it potency and may even be harmful.  If in
doubt about mixing or having fresh product - check with your veterinarian.
By the way the heartworm prevention dosage is the same for dogs - 6 mcg/kg
(mcg is even smaller than a mg).  I am actually using Revolution on my own
ferrets, and so far I am happy with it (even with all the bad post I'm
seeing about it).
 
Carla Christman, DVM
[Posted in FML issue 3089]