Seeing is believing
I have two Jack Russel terriers, both white. When I let my young dog out the back door, to go to the bathroom, a multitude of fleas jumped on her, but I saw them immediately jump right back off. This definitely works and seeing is believing. Neither dog has ever had fleas, and I have used this product for years. I highly recommend the Combo pack. Heartgard works well too. Wonderful protection for dogs.