FDA Approves New Screwworm Treatment for Livestock

American farmers just got a powerful new weapon against a parasite that can devastate entire herds in days.

The FDA has approved Dectomax-CA1 Injectable, the first and only nonprescription treatment for New World screwworm, a flesh-eating parasite that poses a serious threat to livestock across the country. The approval includes a new 100 mL vial size that makes the treatment more accessible to farms of all sizes.

New World screwworm sounds like something from a horror movie, but it's a real danger to cattle, horses, sheep, pigs, and deer. The parasite's larvae burrow into animals' wounds and feed on living tissue, often killing livestock within days if left untreated.

Zoetis Inc. originally received approval for larger vial sizes last October. The new smaller size means even small-scale farmers can afford to keep the treatment on hand without waste.

The FDA also granted emergency use authorization that expands protection beyond beef cattle. Dairy cows, horses, sheep, pigs, and deer can now receive the treatment in specific situations, giving veterinarians and ranchers more options to save animals.

The Ripple Effect

This approval protects more than just individual animals. Screwworm infestations can spread rapidly through herds and across farm communities, threatening food security and rural livelihoods that depend on healthy livestock.

Making an effective treatment available without a prescription means farmers can act fast when they spot early warning signs. Quick treatment stops the parasite before it spreads, protecting entire herds and neighboring farms.

Mike Lormore, director of cattle and pork technical services at Zoetis, says the company continues working with the FDA to expand protection to even more species. Every expansion means fewer animals suffering and fewer farmers facing devastating losses.

The treatment works for prevention too, not just active infestations. Farmers in high-risk areas can now proactively protect vulnerable animals like newborn calves and pregnant cows before problems start.

This is exactly the kind of science-backed solution rural America needs as emerging threats inch closer to U.S. borders.