Frontline Plus for dogs VS Frontline Plus for cats

Is it true that it is the same formula and can be interchanged?

A friend offered me a 4.02ml vile of Frontline PLUS marketed for dogs and told me the chemical difference is so small that you can use .50ml of that as the monthly dose for the cats.


Is this true???

I know it is true that Advantage can be used on either cats or dogs, and is dosed by weight. I'm not so sure about Frontline Plus. Hopefully, someone else can comment about that for you.

I checked up on a few different sites and it seems to be ok but I really hope someone on here knows the deal...

The concentrations of the two medications are different. The dog version is 9.8% Fipronil & 8.8% (S)-Methoprene (by weight). The cat version is 9.8% Fipronil & 11.8% (S)-Methoprene (by weight). While giving the dog version may or may not be harmful, it might be less effective since there is less of the ingredient than is found in the cat version.

According to petshed.com, "In addition, methoprene also has ovicidal and embryocidal effects when applied to female fleas. Note that Frontline Plus for Cats and Kittens contains a higher concentration of (s)-methoprene when compared with the canine versions of the product."