Vet’s Best Flea and Tick Spray kills fleas, flea eggs, and ticks by contact using certified natural essential oils and plant based ingredients like peppermint oil and eugenol, from clove plants. Formula repels mosquitoes too. Safe to use for dogs and puppies 12 weeks or older when used as directed. Can be applied indoors or outdoors. Soothes dog skin to leave them comfortable and smelling fresh. Flea And Tick Spray.