This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.
Researchers Oshin Ley-Garcia, Chunu Mainali, Frank van der Meer, Davor Ojkic, Carolina Malgarin, Bryna Turk, Sylvia L. Checkley, Hannah McKenzie, and Mathieu Pruvot explore the prevalence of significant swine pathgens in 331 wild hogs from the province of Alberta between 2018 and 2024.
Introduction and Objectives: Wild pigs (Sus scrofa), are recognized as one of the most detrimental invasive species in North America, contributing to extensive agricultural damage, environmental degradation, and biodiversity loss. Wild pigs pose a major disease infection risk, as 87% of the swine pathogens listed by the World Organization for Animal Health (WOAH) are transmissible to other species, including wildlife, livestock, and humans. Across the prairie provinces in Canada, the presence of wild pigs coupled with their potential role as reservoirs for economically significant livestock pathogens, has intensified the need for targeted surveillance. This study provides an overview of swine production-limiting diseases circulating within the invasive wild pig population in Alberta.
Materials and Methods: As part of the Alberta Wild Boar Control Program led by the Government of Alberta, 331 wild pigs were captured across the province between 2018 and 2024. Archived samples were tested for 17 swine pathogens using a combination of serological, coprological, and molecular diagnostic methods.
Results: Antibodies to Erysipelothrix rhusiopathiae (120/120; 100%), porcine circovirus 2 (PCV2, 38/120; 31.7%), Mycoplasma hyopneumoniae (Mhyo, 2/96; 2.1%), and porcine reproductive and respiratory syndrome virus (PRRSV, 1/96; 1.0%) were detected. Gastrointestinal parasites were identified for Eimeria spp. (76/192; 39.6%); Metastrongylus spp. (49/192; 25.5%); Trichuris spp. (11/192; 5.7%); Ascaris spp. (11/192; 5.7%); and Strongyloides spp. (8/192; 4.2%). Molecular diagnostics confirmed infection with porcine circovirus 1 (PCV1, 1/331; 0.3%), PCV2 (109/331; 32.9%), porcine circovirus 3 (PCV3, 90/331; 27.2%), rotavirus A (RVA, 21/92; 22.8%), rotavirus C (RVC, 5/92; 5.4%), porcine parvovirus (PPV, 18/101; 17.8%), and Salmonella spp. (2/72; 2.8%). Porcine deltacoronavirus (PDCoV), porcine epidemic diarrhea virus (PEDV), Seneca virus A (SVA), transmissible gastroenteritis virus (TGEV), influenza A virus (IAV), and rotavirus B (RVB) were not detected. Co-detection of pathogens was common, with 55.9% (38/68) of wild pigs testing positive for two or more pathogens.
Conclusions: Overall, wild pigs were infected with pathogens that are significant to the porcine production industry and public health, demonstrating the potential risk of transmission at the wild and domestic pig interface. Although not all screened pathogens were detected, the presence of swine production-limiting and zoonotic agents indicates that wild pigs may contribute to the broader epidemiological landscape of diseases affecting domestic livestock and humans. These findings reinforce the value of wildlife disease surveillance, as monitoring pathogen circulation in wild pigs supports early detection of emerging threats and strengthens risk assessments for domestic swine and human health.
Discussion: PCVs were among the most frequently detected viral pathogens in Alberta wild pigs. The high frequency of PCV2 and PCV3 is consistent with their widespread occurrence in Canadian domestic pigs, while comparable detection levels reported in wild-pig populations in other countries further indicate that these viruses circulate widely in free-ranging wild pigs. Age and sex were significantly associated with PCV2 and PCV3 infection, with mature and female individuals exhibiting a higher risk (p< 0.001) of being infected. These associations may reflect cumulative exposure with age, differences in social behaviour and contact patterns among demographic groups, prolonged persistence of infection, or temporary protection of juveniles by maternally derived antibodies.