I have been a boycotter of Hartz products since I was 15. I was the primary care taker of the family dog and therefore it was my responsibility to flea bathe and dip. My perfectly healthy 5 year old sheltie developed cancer and had to be put down. In trying to find out how and why this happened I researched everything I fed to him or put on him and found that it was most likely the flea control products I had used. Even Hartz’s disclaimer states “may cause cancer in some animals”. I also feel that in this day and age there is no need to use the outdated methods of flea control. We do not use dips, medicated shampoos or flea collars. The way to go is frontline, advantix or program. We use it during the late spring/summer months and discontinue when the weather gets cold. We use this in conjunction with natural remedies such as brewers yeast and plenty of excercise, which my vet says will help flea control. I have three dogs, one cat and a big yard. I have not seen a single flea in years.