The U.S. Food and Drug Administration (FDA) has granted conditional approval for EXZOLT™ CATTLE-CA1 (fluralaner topical solution), a new pour-on parasiticide developed by Merck Animal Health. The product is reportedly the first isoxazoline-class treatment authorized for cattle and is conditionally approved for both the prevention and treatment of New World screwworm larvae, as well as for the treatment and control of cattle fever tick. The approval was issued based on safety data and a reasonable expectation of effectiveness from recent global studies. Conditional approval allows veterinarians and producers access to the product while additional effectiveness data are generated. EXZOLT CATTLE-CA1 is approved for use in beef cattle two months of age and older and in replacement dairy heifers under 20 months. It is not approved for breeding bulls, dairy calves, or veal calves. The product carries a 98-day meat withdrawal period. The topical solution will be available by prescription in 1-liter and 5-liter volumes starting in early 2026. Its use is limited to the labeled indications under federal law. The product also recently received market authorization in Mexico for use against New World screwworm. For more information on the product, visit the Merck Animal Health website.
