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Aug 27, 2026 · Archive
Science

FDA Authorizes Generic Ivermectin as Emergency Screwworm Shield for Cattle

The Feb. 5, 2026 order let regulators bypass a full efficacy review as the parasite closed in on US herds.

  • Ivomec (ivermectin) is sold over the counter, no veterinary prescription required, under the new authorization.
  • Cattle qualify for treatment within 24 hours of birth, at castration, or upon a fresh wound.
  • Screwworm larvae reached Nuevo Leon, Mexico, just 70 miles from Texas, by September 2025.

Why it matters: Emergency clearance for a decades-old generic means the border and sterile-fly barriers already failed to hold the line.

FDA Press ↗ · Aug 27, 20268/27/26