FDA Grants Conditional Approval for New Cattle Drug to Combat New World Screwworm

The U.S. Food and Drug Administration has conditionally approved a new topical medication for cattle, Exzolt Cattle-CA1 (fluralaner), offering a novel treatment and preventative measure against New World screwworm infestations and cattle fever tick, according to a recent announcement. This marks a significant development for the livestock industry, providing producers with an additional tool to manage two serious parasitic threats. While New World screwworm has not been detected in the United States, cattle fever tick is an ongoing concern for the health and productivity of cattle herds.

The conditional approval signifies that the FDA has determined Exzolt Cattle-CA1 to be safe and possesses a reasonable expectation of effectiveness for its intended applications. This regulatory pathway allows for the drug to be made available to producers while the sponsor, Intervet, Inc. of Rahway, New Jersey, gathers further data over a five-year period to support a full FDA approval. The drug is indicated for beef cattle two months of age and older, as well as replacement dairy heifers under 20 months of age. For New World screwworm, it is approved for prevention and treatment of larval infestations. For cattle fever tick, it is approved for treatment and control.

The FDA’s Center for Veterinary Medicine emphasized its commitment to ensuring that animal health products are both safe and effective, thereby safeguarding the nation’s food supply. This conditional approval was facilitated by Exzolt Cattle-CA1’s eligibility under the Priority Zoonotic Animal Drug (PZAD) designation, a provision established by the Coronavirus Aid, Relief, and Economic Security (CARES) Act. This designation is granted to drugs intended to treat or prevent serious or life-threatening diseases in animals, address unmet animal health needs, and where demonstrating effectiveness requires complex studies.

For consumers, a key aspect of this approval relates to food safety. To prevent unsafe drug residues in meat, Exzolt Cattle-CA1 has a withdrawal period of 98 days before treated cattle can be slaughtered. The drug is not approved for use in lactating dairy cattle, dairy calves, veal calves, or bulls over one year old intended for breeding. Exzolt Cattle-CA1 is a prescription-only topical solution, administered directly onto the animal’s back along the dorsal midline. It is available in 250 mL, 1-liter, and 5-liter bottles and is a ready-to-use product. Producers and veterinarians are advised to use antiparasitic drugs like Exzolt Cattle-CA1 only when medically necessary, adhere strictly to product labeling, and integrate such treatments into broader parasite management strategies.

Article by Mel Anara, based upon information from the U.S. Food and Drug Administration.

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