Farmscape for November 21, 2025

The Swine Health Information Center reports the identification of PRRS in wean to finish continues to rise with the lineage L1C becoming the most prominent.
As part of its November eNewsletter the Swine Health Information Center has released its monthly domestic and global swine disease monitoring reports.
SHIC Associate Director Dr. Lisa Becton says PRRS activity continued to rise in wean-to-market sites, accompanied by a surprising decrease in sow farm positivity.

Quote-Dr. Lisa Becton-Swine Health Information Center:
PRRS continues to be a disease of interest and wean to finish pigs have a 43.6 case positivity and sows only had a 17 percent case positivity.
However, the lineage L1C really is surging and we do see this as the predominant case identified.
There has already been over 36 hundred cases in 2025 and this surpasses the 2024 total.
In addition, L1C has surpassed both L1A and L1H for lineages seen.
What this does is continues to let us know what strains are circulating, because L1C can be more virulent than we do see in other viruses, so it really does help to drive home the issue of biosecurity in sites, to assess what's going in in different sites or states, especially if you have to move animals across lines and assess those different risks.
It also helps to identify what are some strategic interventions that potentially could be done, such as vaccination?
This does give producers and veterinarians the ability to see what's active out in the industry and be able to react in their own herds and reduce the threat of this virus incursion.

The Swine Health Information Center's domestic and global swine disease monitoring reports can be assessed at swinehealth.org.
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Bruce Cochrane.

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