I work at a veterinarian office, and I have seen first-hand incidences of reactions to many O.T.C. flea preventions. We had a lady come in that had bathed her 3 cats in Sergents flea & tick shampoo for cats, and they all died within a day of each other. She was so devestated that we had to call a friend of hers to pick her up from the office. The one that lived the longest, died after $800+ of life saving medicine. We are still working with her and helping her out. Not all veterinarian offices are as understanding, but a lot will help out in times of emergencies if you are willing to make an effort! So don’t feel like you can’t take your pet to the vet’s office because you don’t have the money. ESPECIALLY in cases like these! Even though there is no guarantee, we have saved most of the 10 cases of reactions to flea products this year. I am doing my best to educate the public and companies that sell the terrible stuff! I even have a “No-Hartz” sticker on my nametag. Keep up the good work! We will get them soon I know it!