Texas A&M releases screwworm fact sheet for swine producers
Guide covers risk factors, prevention and reporting procedures
9 June 2026
2 minute read
By: The Texas A&M AgriLife Extension Service has released a new fact sheet on New World screwworm to help swine operations prepare for and protect against the potentially devastating parasite.
The new fact sheet – The New World Screwworm, NWS, Threat to Swine Producers – provides research-based information on risk factors, prevention steps and reporting guidance for the swine industry to respond quickly if cases are suspected.
The fact sheet is the latest addition to AgriLife Extension’s online information hub, which includes additional fact sheets – some in Spanish, a technical bulletin and related prevention information.
Inspection and care
Every pig must be inspected daily for signs of wounds and infestations, the experts state. Proper wound care and prevention are critical, as even small breaks in the skin or natural openings can serve as sites for egg-laying and larval development.
Swine producer management practices for New World screwworm should include:
- Identifying production and housing conditions that increase risks of wounds.
- Implementing effective biosecurity, environmental and wound management practices.
- Knowing the response procedures for suspected infestations.
- Developing a New World screwworm disaster management plan.
Risk factors for wounds
The new swine fact sheet identifies several factors, including both routine management practices and pig injuries, that can cause breaks in the skin and increase the risk of myiasis or the infestation of an animal with fly larvae or maggots.
Risk factors include:
- Piglet processing, such as ear notching or tagging, castration, tail docking, tattooing or needle teeth clipping.
- Adult animal management, including vaccination or ear tagging.
- Any needle injection, regardless of the size of the needle or route of administration.
- Umbilical sites in newborn piglets.
- Skin abrasions or wounds from shoulder sores, fighting behavior, group mixing, rough flooring, sharp or broken feeders, pen structures, water drinkers, etc.
- External parasite irritation, including bites from ticks or lice.
The authors recommend oral medications or vaccines over injections, when possible. For management practices in which wounds are unavoidable, use methods that cauterize or seal the tissue to reduce bleeding and exposure of fresh tissue, the authors advised.
Additionally, apply topical treatments that promote healing and protect the wound site from fly activity. Producers should work with a veterinarian to develop an appropriate wound care plan and identify products approved for use in swine.
Authors of the fact sheet are Jeffrey Wiegert, Ph.D., AgriLife Extension swine specialist and associate professor, Texas A&M Department of Animal Science, Bryan-College Station; Guilherme Verocai, Ph.D., associate professor and director, Parasitology Diagnostic Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences; and Sonja Swiger, Ph.D., AgriLife Extension entomologist and professor, Texas A&M AgriLife Research and Extension Center at Stephenville, and Phillip Kaufman, Ph.D., department head, Bryan-College Station, both in the Department of Entomology.
