12/05/2025
FDA Conditionally Approves Topical Drug for Cattle for New World Screwworm and Cattle Fever Tick
For Immediate Release:
December 04, 2025
Today, the U.S. Food and Drug Administration conditionally approved Exzolt Cattle-CA1 (fluralaner) topical solution for the prevention and treatment of New World screwworm (NWS) larval infestations, and the treatment and control of cattle fever tick in beef cattle 2 months of age and older and replacement dairy heifers less than 20 months of age.
“This conditional approval gives cattle producers a new tool to combat two parasites threatening the well-being of cattle in the U.S.,” said FDA Commissioner Marty Makary, M.D., M.P.H. “Although NWS has not been detected in the U.S., cattle fever tick is here. This is the first drug conditionally approved by the FDA specifically for the control and treatment of cattle fever tick.”
This conditional approval means the FDA has determined Exzolt Cattle-CA1 is safe and has a reasonable expectation of effectiveness for its intended use. The sponsor, Intervet, Inc. of Rahway, New Jersey, has up to five years to generate the additional effectiveness data needed to support a full FDA approval.
“The FDA is leveraging every resource and authority at its disposal to ensure producers and veterinarians have the critical products they need to protect their livestock and safeguard our food supply against NWS and cattle fever tick,” said Timothy Schell, Ph.D., director of the FDA’s Center for Veterinary Medicine. “We remain steadfast in our commitment to ensuring that animal drugs are safe and effective and that food from treated animals is safe to eat.”
Exzolt Cattle-CA1 is eligible for conditional approval because it is intended to prevent and treat serious or life-threatening diseases in cattle, it addresses unmet animal health needs, and demonstrating effectiveness of the drug requires complex or particularly difficult studies. Exzolt Cattle-CA1 received expedited review through a priority zoonotic animal drug (PZAD) designation, an authority provided to the FDA under the Coronavirus Aid, Relief, and Economic Security (CARES) Act.
To prevent unsafe drug residues in meat from treated cattle and ensure human food safety, the slaughter withdrawal period for Exzolt Cattle-CA1 is 98 days. This product is not for use in lactating dairy cattle, dairy calves, veal calves, or bulls at least 1 year old that are intended for breeding.
Exzolt Cattle-CA1 topical solution is available by prescription only and dispensed in 250 mL, 1L and 5L bottles. The single-use, ready-to-use product is applied directly to the hair and skin in a narrow strip extending along the top of a bovine’s back from between the shoulder blades to the base of the tail (withers to tailhead along the dorsal midline).
Antiparasitic drugs such as Exzolt Cattle-CA1 should be used only when medically necessary, in accordance with the product labeling, and as part of a comprehensive parasite management strategy.
https://www.fda.gov/news-events/press-announcements/fda-conditionally-approves-topical-drug-cattle-new-world-screwworm-and-cattle-fever-tick
