I've switched to a non-toxic anti-flea product called Only Natural Pet All in One Flea Remedy for dogs and cats. Basically, it's diatomaceous earth, or DE, a mineral from prehistoric algae fossils. Has apparently been used for pest control in agriculture and gardening for centuries. It seems to work, though haven't tested it in the coastal south where beach fleas swarm. Some articles about natural flea control appear here and here and here. PLUS here are links to NRDC's very good Simple Steps backgrounder and excellent Green Paws Pocket Guide about commercial flea and tick products - what to avoid, what to look for.
