My dogs have fleas. My husband bought and put sentry flea and tick on them because he was looking at the price not the effectiveness of it, so I have no idea if it will work. We normally use k9 advantix but now I’m stuck with this stuff for at least a month before I can put the good stuff on. I’m due at the end of June and am really uncomfortable bringing a newborn baby into a house that has fleas. FYI I cleaned the carpets the days before we found out about the fleas so hopefully that’s helpful. But I still am completely overwhelmed.