# FDA approves Merck drug for decimated cattle herds to stop screwworm

> The FDA granted conditional approval to Merck Animal Health's EXZOLT CATTLE-CA1 pour-on for preventing and treating New World screwworm. The product can also treat cattle fever tick.

- Date: 2025-12-09 · published 2025-12-09T12:00:00.000Z
- Category: disease · region US · magnitude medium
- Page: https://feedsoft.ai/events/21455-fda-approves-merck-drug-for-decimated-cattle-herds-to-stop-screwworm
- Commodities: [Live Cattle](https://feedsoft.ai/c/LCATTLE.md)

## Why it matters

A licensed treatment gives US ranchers a new tool against screwworm, which could reduce the risk of an outbreak that would hit cattle supply and prices.

## Read by commodity

- LCATTLE: neutral

## Similar past events

| Commodity | Date | Event | 5-day % | 20-day % |
| --- | --- | --- | --- | --- |
| LCATTLE | 2025-02-24 | [APHIS Allows Imports of Mexican Cattle to Continue Despite 2nd New World Screwworm Case](https://feedsoft.ai/events/25983-aphis-allows-imports-of-mexican-cattle-to-continue-despite-2nd-new-world.md) | -0.8% | +2.9% |
| LCATTLE | 2023-08-05 | [Costa Rica Battles Cattle Screwworm Outbreak](https://feedsoft.ai/events/34505-costa-rica-battles-cattle-screwworm-outbreak.md) | +0.4% | -0.8% |
| LCATTLE | 2024-12-19 | [USDA allocates $165M to protect livestock from New World screwworm \| Agriculture Dive](https://feedsoft.ai/events/26913-usda-allocates-165m-to-protect-livestock-from-new-world-screwworm-agriculture.md) | +0.5% | +3.6% |
| LCATTLE | 2017-08-16 | [New World Screwworm Still a Threat \| Ohio BEEF Cattle Letter](https://feedsoft.ai/events/69399-new-world-screwworm-still-a-threat-ohio-beef-cattle-letter.md) | -3.9% | -6.2% |
| LCATTLE | 2025-02-18 | [USDA will not ban cattle imports from Mexico over latest screwworm case, agency says \| Reuters](https://feedsoft.ai/events/25979-usda-will-not-ban-cattle-imports-from-mexico-over-latest-screwworm-case-agency.md) | -0.5% | +2.4% |

## Sources

- cnbc.com: https://www.cnbc.com/2025/12/09/fda-merck-screwworm-treatment-cattle-herd-decline.html

---
Data from Feedsoft AI (https://feedsoft.ai/). For information only; not investment advice.