How do I pick the right flea and tick treatment for my dog? What does Seresto do that Frontline doesn't? How long does this last and does it expire? My flea and tick treatment isn't working anymore, why? These are all frequently asked questions. With all the different brands for flea and tick treatments for your dog or cat, how do you choose? Let's break it down for you, so you can shop with a little information that'll make this much-needed process a painless one.