Within an hour of applying Sentry Pro XFC to both our Golden Retriever and Black Lab/Border Collie mix (both 6 years old), they suffered a severe reaction to this product. They both were in agony, could not sit still for more than a few seconds and were scratching themselves until their skin was raw. After looking at the application site, it had clearly burned their skin. I immediately gave both dogs Benedryl, but the reaction to this product has lasted 2 weeks already. They are definitely not themselves - their energy level has diminished and... read full review »