I went to the Bayer site and this is what they say the dose should be for different weights of cats:
Kitten (weighing 2-5 lbs.) 0.23 ml Gerald
Small cat (5-9 lbs.) 0.4 ml Lily
I just put 0.4 ml on my four month old kitten, who weighs over 5 lbs. I have a package of six large cat tubes, that I got for my adult cats. I put some white cloth tape with the bottom around the 0.4 mark on the 1.0 ml syringe because I heard Advantage II would take the numbers off the syringe. Shake the tube well. I put on gloves and expressed the fluid onto a disposable plastic teaspoon and drew it up. I thought I was putting it in the proper spot on his back, where he couldn't get at it and put all the other kittens/cats in other rooms, because I think what happened when I put Cheristin on him, is some got rubbed off when a Cat Dancer toy brushed against his back, and he ended up getting fleas. He has now scratched the spot with his paw and licked it twice and winces and drools and gags for a little while. I hope he is going to be okay. I put the Advantage II on him six days earlier than when the when the month would be up. I have been giving him CapGuard every other day at first and then every day, so he got about eight CapGuard doses so I could get him closer to the time the month would be up, after putting the Cheristin on him. It is really hard to get the medicine on in the correct place with a kitten that doesn't want to hold still. I was able to get most of the left overs back in the tube, by gently squeezing the tube when upright and then quickly putting the end of the tube in the fluid and unsqueezing it.
Good luck if you haven't already put the Advantage II on your kittens.
Funny...just did the exact same thing, went to CVS and asked the pharmacist for 'smallest, needle free insulin syringe' and she gave me three. They have tons. It wasn't a problem or issue at all....hope this helps.