Sort & Cull

No set date has been released for the resumption of live cattle trade from Mexico to the U.S., according to the Animal Plant and Health Inspection Service (APHIS). A halt was ordered on Nov. 25, 2024, following the detection of New World screwworm (NWS) in southern Mexico.

C. Natanauan, a member of the customer support team with APHIS Veterinary Services, strategy and policy, live animal import and export, told DTN on Friday that protocols are currently being drafted for the importation of horses regarding NWS, but there is no definite date for resumption. For cattle, the NWS protocol is still in progress, with no resumption date yet either. Other news sources had reported this week that the ban would end Jan. 20, which was not true, according to APHIS information.

The restrictions were put in place by APHIS in late November due to the severity of the threat from NWS and its movement northward from Central America into Mexico.

NWS DETAILS, SYMPTOMS

NWS are fly larvae that infest living tissue of warm-blooded animals, causing infection. According to APHIS, these maggots will burrow into a wound, feeding as they go and doing extensive damage by tearing the host's tissue with sharp mouth hooks. The wound becomes larger and deeper. NWS can cause serious, even deadly, damage to the animal.

The adult screwworm flies are about the size of a common housefly with orange eyes, a metallic blue or green body, and three dark stripes along their backs.

Affected mammals and birds show signs of irritated behavior, head shaking, smell of decay, evidence of fly strike, and presence of fly larvae in wounds.

APHIS said the best prevention of NWS in the U.S. is by avoiding infestation. Producers should be alert to symptoms in pets and livestock, ensure that pets traveling internationally are inspected for screwworm, and check their vehicles for screwworm flies if they are in an NWS-infested area.

There is a constant threat of NWS due to it being detected so close to the U.S. APHIS is releasing sterile flies through aerial and ground release at strategic locations throughout Central America and is working to eradicate NWS from the affected areas to reestablish the biological barrier in Panama.

Jennifer Carrico can be reached at jennifer.carrico@dtn.com

Follow her on social platform X @JennCattleGal

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