Guide

Repel versus kill

Most flea-and-tick products are courtroom justice: the pest bites, the pest dies. Repellency is a locked gate: with K9 Advantix II, fleas, ticks and mosquitoes are repelled and killed on contact — they don't have to bite the dog to die.

That difference is not academic. Ticks transmit Lyme, Rocky Mountain spotted fever and Ehrlichiosis through the bite itself; mosquitoes are the heartworm vector. Fewer completed bites means fewer chances for any of it to change hands.

It's also the reason for the cat warning: the repellent ingredient, permethrin, is exactly what cats can't process. The same molecule that locks the gate for dogs is the one that must never touch a cat — the two facts travel together.