(Virbac) Effitix Topical Solution for Dogs kills and repels ticks, fleas and mosquitoes; kills lice; aids in the control of mites; prevents and inhibits blood feeding by biting flies. For use on dogs 12 weeks of age and older. Effitix combines the killing action of fipronil with the repellency of permethrin for rapid and long-lasting protection. Do not reapply sooner than every 30 days. Do not use on cats.