Detection of PCV2d in pig industry of the Iberian Peninsula.

Porcine circovirus type 2 (PCV2) is a major viral pathogen affecting swine worldwide, causing significant economic losses through its association with porcine circovirus-associated diseases (PCVD), which can lead to reproductive failure, growth retardation, and increased mortality in affected herds. Although vaccination against the PCV2a and PCV2b genotypes has reduced clinical disease, the PCV2d genotype is increasingly prevalent in many regions. Molecular detection was performed on fecal samples from collected from a slaughterhouse using PCR targeting the ORF2 gene to detect PCV2 genotypes. Of 400 samples tested, 8.5% (17/200; 95% CI: 5.03-13.26) of samples from Portugal were positive for PCV2d, while none from Spain tested positive. This study reports the first confirmed detection of PCV2d in domestic pigs in Portugal in indexed journals, indicating circulation within the Portuguese swine population. The absence of PCV2 in Spanish samples may reflect differences in regional epidemiology or biosecurity practices. These findings highlight the importance of ongoing molecular surveillance and farm-level monitoring to inform vaccination strategies and control measures in response to evolving PCV2 genotypes. Integrated approaches should also consider wildlife reservoirs and environmental factors to improve management of PCV2 spread in domestic swine.