Dec 08, 2025

Conditional Approval of Topical Screwworm Treatment

Posted Dec 08, 2025 5:00 PM

Merck Animal Health announced that the Food and Drug Administration granted conditional approval for EXOLT CATTLE-CA 1. It’s a new topical that’s approved for the prevention and treatment of infestations caused by New World Screwworm larvae, as well as the treatment and control of the cattle fever tick.

“The New World Screwworm represents a growing concern to U.S. agriculture, potentially causing devastating economic losses for cattle producers that could reach hundreds of millions of dollars,” said Rick DeLuca, president of Merck Animal Health. “We worked closely with the FDA to accelerate availability so that veterinarians and cattle producers will have access to a powerful new tool to protect cattle from these serious parasites, helping to safeguard the industry’s economic future and the nation’s beef supply.” Merck also received market authorization in Mexico to prevent and treat the New World Screwworm to help control the spread of the parasite and protect cattle. 

-NAFB