There was a supplement to Compendium with the April 2001 issue of
Compendium that has a good article on using Advantage on ferrets ( 1 tube
of the small size cat per ferret). In your case, you are going to have
to treat ALL of the dogs, cats, and ferrets. Plus spray the yard and the
house to get this flea problem under control. You might want to consider
using Frontline spray to treat all of the pets and to keep the cost down.
Hope that helps,
Jerry Murray, DVM
[Posted in FML issue 3506]