The Swine Health Information Center (SHIC) reports a notable shift in swine disease trends during April, according to insights shared in its May eNewsletter. While PRRS and PED activity increased, a decline in Mycoplasma hyopneumoniae detections offers a positive sign.
SHIC Associate Director Dr. Lisa Becton highlighted several key findings from the latest domestic and global surveillance reports:
PRRS (Porcine Reproductive and Respiratory Syndrome)
April 2025 saw the highest PRRS case positivity rate for any April since 2018, particularly impacting the wean-to-finish age group. The L1C.5.32 variant had the highest detection rate of any PRRS variant this year. In total, this strain—along with others tracked through ORF5 sequencing—accounted for 42% of all ORF5s recovered from veterinary diagnostic labs.
PED (Porcine Epidemic Diarrhea)
There was a regional spike in PED cases, especially in sow herds in Minnesota. This aligns with expected seasonal increases but remains a concern for producers in affected areas.
Influenza A
As anticipated, seasonal increases in influenza A case positivity were observed during April.
Mycoplasma hyopneumoniae
Encouragingly, Q1 2025 had the lowest historical positive cases confirmed through tissue diagnosis, signaling progress in controlling this endemic disease.
Dr. Becton emphasized that enhanced biosecurity protocols remain the cornerstone of disease prevention. Strong on-farm biosecurity not only helps with ongoing challenges like PRRS and PED, but is also a critical defense against potential foreign animal disease threats.
Producers are encouraged to review the full domestic and international disease surveillance updates now available on the SHIC website at swinehealth.org.
