06/05/2026
Hey everyone, Dr. Misner here! The USDA announced yesterday that a case of New World Screwworm was detected in a calf in Texas. Why does this matter?
New World Screwworm (NWS) is a fly that can burrow into living flesh in the maggot stage. A normal fly's maggot stage only affects dead or damaged tissue for comparison. The USDA has been closely monitoring this pest along the US/Mexico border and they are already taking action with increased monitoring and the release of sterile flies.
This pest can affect livestock, companion pets like dogs and cats, as well as people. Since summer is the season of travel, it's important for you to know about the potential for this parasite especially if you are heading south or traveling internationally. If you are traveling south or internationally with your pets and you notice any wounds or areas of irritation, reach out to a veterinarian immediately. This is especially important if the wound seems to be getting worse instead of better, has abnormal draining tracts, or you can physically see parasite activity/eggs in the wound.
The resource below can be helpful in providing further information. As always, if you have any questions at all please let us know and we are happy to help!
Get essential prevention guidance to protect livestock and other animals from New World screwworm, including early detection, management tips, and APHIS resources.