Clint, this is still a friendly list. I'm glad to hear you brought Elmer inside. Ferrets can stand up to about 82 or so degrees comfortably provided there is shade and water - over that you can start to expect trouble. Ferrets have very poor heat dissipation capabilities as compared to other domestic species. Ferrets can get heat prostration when temperatures are in the eighties. Ferrets in heat trouble will initially start panting, then go limp, and eventually lose touch with their surroundings. Body temperatures can reach 108 degrees or more, literally cooking the internal organs and brain. No ferret lasts long like that. hBest to keep Elmer inside during the summer..... As far as heartworm prevention is concerned - you need to check with your vet. It is not available over the counter, nor should it be. Overdosing is toxic, and for ferrets, it generally has to be dosed rather precisely. Fleas can be a problem. The three largest groups of flea products are the organophosphates, the carbamates, and the pyrethrins. Of the three, pyrethrins is the ONLY one that I recommend for use on ferrets. You can also use it on kittens or puppies. Pyrethrins is a natural product of chyrsanthemums, although now a lot of pyrethrin compounds are synthesized in laboratories. However, they are all safe, and I have not seen any problems with their use in ferrets. Organophosphates ( the most common ingredient in flea powders), and carbamates on the other hand, can be toxic if applied in high doses. The signs of organophosphate toxicity is the paralysis-like syndrome that you described above, in addition to dilated pupils, drooling, loud stomach rumbles, etc. Severely intoxicated animals may stop breathing, or may have long-lasting neurologic effects. Organophosphates, in highly potent concentrations, are the leading component of nerve gas. While adult dogs and cats may tolerate this material externally for the killing of fleas, smaller animals such as ferrets are highly susceptible to overdosage. You may use organophosphate-based products for your rugs and house (in moderation), but not on your ferret. If it doesn't say pyrethrin on the label, put it back. For best results, call your vet for instructions prior to using any flea product on your ferret. Bruce Williams, DVM Department of Veterinary Pathology [log in to unmask] Armed Forces Institute of Pathology (202) 576-2453/2454 Washington, D.C. 20306-6000 [Posted in FML issue 0875]