I decided to open a thread about flea meds because so many of them are changing active ingredients. I just bought some today after looking through all sorts of options. I chose to stick with the pyrethroid family since its been around longest and my dogs have never had an adverse reaction to them. I got phenothrin though which I've never used. The oral toxicity is 10,000mg/kg in labratory rats. I'm a litle wary of trying fipronil on my dogs (which is the current popular stuff) because it is way more toxic, 97mg/kg oral toxicity. Has anybody been using fipronil products? Have you had any problems?