New World Screwworm Updates: 

Protect Your Herd: 

Preventing an infestation of NWS is key. Treatment can be difficult, and eradication is expensive. NWS are attracted to the open wounds and mucus membranes where they lay their eggs, and they can be carried by both domestic and wild animals. We recommend taking steps to quickly identify and treat open wounds and keeping wildlife away from your cattle to the extent possible. 

• Frequently inspect cattle and pay close attention to tick bites, cuts, and dehorning/branding sites. Immediately treat any open wounds, scratches, or scabs. Screwworms in wounds are killed by direct application of a wound dressing. 
• Closely monitor new calves and mothers. NWS often lay eggs on the navel areas of calves, and the vulva and perineum of cows. On bulls and steers, monitor the sheath/prepuce as well.  
• Pay close attention to nasal passages and eyes for signs of larvae (maggot) infestation. 
• Minimize access of wild animals (birds, feral hogs, etc.) to cattle to the greatest extent possible. 
• Practice good biosecurity measures like frequently cleaning clothing, boots, vehicles, and equipment on your farm or ranch. 

Click here for more information on NWS