I used to use half an application of Frontline on mine. The weight was up to 22 pounds...and they weighed far less than that. It still worked.
The cats I never divided because the weight limit was closer to what mine weighed.
The packaging has changed on frontline...you get a vial with the product and an applicator.
I'm sure you know...but don't put dog flea medication on a cat.
__________________ Deb, Reese, Reggie, Frazier, Libby, Sidney, & Bodie |