One of the top concerns remains porcine reproductive and respiratory syndrome (PRRS), which costs the U.S. swine industry more than $1 billion in lost productivity annually. PRRS, once known for its seasonal behavior — typically surfacing around mid-October — has become increasingly unpredictable. In an unusual trend, cases surged in April and May 2025, a time when the virus would normally subside. Of particular concern is the emergence of new variants, including the 1-4-4 L1C.5 strain, currently circulating in U.S. herds.
Swine health experts, along with veterinarians and producers, play a critical role in responding to the threat. The Swine Health Information Center (SHIC) provides timely data on PRRS outbreaks, including where the virus is spreading — by region, state, or farm type (e.g., sow farms vs. wean-to-finish). This information helps farmers create action plans to reduce disease transmission.
Another familiar foe — porcine epidemic diarrhea virus (PEDV) — has made a notable comeback. Many producers are comparing the current spike to the major outbreak in 2013–2014. Although the virus remains endemic in the U.S., stringent biosecurity protocols implemented after the last major outbreak had helped curb its spread. However, with the resurgence of cases, concerns over biosecurity fatigue have grown. Experts stress that renewed attention to biosecurity is vital, not only for PEDV but also for other swine diseases.
A new threat: New World screwworm (NWS) has also raised alarm. This parasitic fly lays its eggs and larvae in open wounds and mucous membranes of warm-blooded animals — including pigs, cattle, wildlife, and even humans. NWS was detected in Mexico in November 2024 after years of absence, and in May 2025, new cases were found in Veracruz, just 700 miles from the U.S. border. In response, the U.S. Department of Agriculture (USDA) temporarily suspended live cattle, horse, and bison imports from affected border regions.
To address this emerging risk, SHIC and the American Association of Swine Veterinarians will host a webinar on June 13, covering the latest updates on NWS, including clinical signs, life cycle, spread in Mexico, and prevention strategies.
Meanwhile, researchers are also monitoring the H5N1 avian influenza virus, which poses a potential threat if it crosses over from birds to pigs — a possibility currently under investigation.
Whether it’s PRRS, PEDV, NWS, or other viral and bacterial threats, maintaining a strong working relationship between producers and veterinarians remains vital. Early detection, herd observation, and strict health protocols are essential for keeping pigs market-ready — and for ensuring that producers can benefit from favorable market conditions.
farmprogress.com