New World Screwworm Confirmed in Arizona Animals; California Tightens Pet Entry Rules
Arizona has confirmed five cases of the New World screwworm parasite in animals, including horses, dogs, and sheep, primarily in the eastern and southeastern parts of the state. In response, the U.S. Food and Drug Administration has authorized an emergency…
Phoenix, AZ, November 10, 2026 —
Arizona has reported five confirmed cases of the New World screwworm parasite affecting animals across the state. The parasite has been identified in horses, dogs, and sheep, with the majority of cases located in the eastern and southeastern regions of Arizona.
The New World screwworm is a parasitic fly that lays its eggs in the open wounds of warm-blooded animals. The larvae hatch and feed on the living flesh of the host animal, which can lead to severe injury, infection, and potentially death if left untreated.
In response to the growing concern, the U.S. Food and Drug Administration (FDA) has granted an emergency use authorization for Bravecto chewable tablets. This medication is now authorized for the treatment of screwworm infestations specifically in dogs and puppies. The authorization aims to provide a treatment option for affected canine populations.
Further measures have been enacted by neighboring states to prevent the spread of the parasite. California has implemented new entry requirements for pets traveling from areas in Arizona where the screwworm has been confirmed. These requirements are intended to safeguard animal health within California.
Details regarding the specific timeline of the confirmed cases or the exact locations within eastern and southeastern Arizona were not provided in the summary. The number of animals affected beyond the initial five confirmed cases has also not been detailed. Information on any broader containment or eradication efforts beyond the FDA’s authorization for dog treatment and California’s pet entry requirements was not available.
Story summarized from the original created by Karina Bazarte on www.azfamily.com, see more information here.
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