You don't say what treatment you have.
I know for fact that ALL Frontline weight sizes have the same concentration of active ingredients (%drug in liquid); the only change is the total amount of liquid.
This information is clearly listed on the packages and the product inserts.Use Frontline Plus for Dogs (fipronil 9.8% and S-methoprene 8.8%) on dogs and puppies 8 weeks or older. Frontline Plus for Dogs is available as 0.67 ml applicators for use on dogs and puppies up to 22 lbs, 1.34 ml applicators for dogs 23-44 lbs, 2.68 ml applicators for dogs 45-88 lbs and 4.02 ml applicators for dogs 89-132 lbs.
We use this FACT (same drug concentration) to save money by purchasing the largest weight size and then measuring out some of the liquid for each dog based upon its weight.
0.67mL will treat up to 22lbs: 0.67mL/22lbs = 0.03mL/lb
1.34mL will treat up to 44lbs: 1.34mL/44lbs = 0.03mL/lb
2.67mL will treat up to 88lbs: 2.67mL/88lbs = 0.03mL/lb
4.02mL will treat up to 132lbs: 4.02mL/132lbs = 0.03mL/lb
I simply draw out of the package with a syringe&needle the desired volume of drug, remove the needle from the syringe, and then apply to the back of our dogs with the blunt end of the syringe. Any left over drug I save in a glass vial for the next time we treat.
The weight ranges also provide you with what the drug company thinks are safe maximum doses.
1.34mL will treat from 23lbs = 0.058mL/lb
2.67mL will treat from 45lbs = 0.059mL/lb
4.02mL will treat from 89lbs = 0.045mL/lb
