I did some research this morning online for Comfortis, the flea pill. That stuff can be expensive (upwards of $100/6) but I found a site (petmedsnmore) that is reasonable ($57/6). We have two big dogs (60 & 90 lbs) and two cats (both over 15 lbs). The Comfortis is not okay for cats but we are considering it for the dogs. Has anyone who has used it had their dogs get sick (vomit) at first? Apparently this is a common side effect?