I was given a great tip to save money onflea medicine. I was told that when I buy "advantage" to buy the bigger tubes fordogs and measure out with a syringe or dropper the approiate amount for my cats. The problem is I dont know how much to measure? I have one large cat and the others are of average weight.I would really appreciate any help on this. My cats are starting to scratch This tip really saved me some money, also I found a great Pet site called Pet Shed (on line) they have great prices on flea meds and very reasonable shipping!!