The VetGun Horn Fly Control Device allows the cattle raiser to protect his herd from horn flies out in the field or in the feedlot safely with a simple pull of a trigger-no herd confining, handling, or additional labor required. Administered on foot, horseback, or by ATV/UTV from up to 30 feet away, the CO2-powered VetGun 'shoots' a precise-dosage pellet of the topical insecticide lambda cyhalothrin onto the animal's hide, where it's then absorbed into the body. One person can reportedly dose cattle in a fraction of the time required by other methods with less stress to both man and animal.