Your the first post that was aware of the counterfeits. I have been telling my clients that the Co-Ops, Tractor Supply, Catalog veterinary drug dealers, Pet Med Express and many of the chain feed stores get their Frontline and Advantage from questionable suppliers. This has been going on for years and I have been dealing with the feedback and problems with them for over 25 years. Only a veterinarian has the product from the direct supplier and it is the integrity of the veterinarian that guarantees that the product is the original. Unfortunately, there are some greedy vets that sell their souls to get the products to the public...damn the problems and side effects.
About two years ago I even got to see some Frontline being sold in a Co-op that didn't even have the words on the packaging spelled correctly. As the adage states, you get what you pay for....