Small Ruminant Lentivirus Infection in Sheep and Goat in North Portugal: Seroprevalence and Risk Factors

Small ruminant lentivirus (SRLV) are infected and transmitted among ovine and caprine species. This disease is a severe problem for small ruminant production, not only for animals’ wellbeing but also for the herd’s efficiency. The main aim of this research was to quantify the seroprevalence and associated risk factors for SRLV infection in the north region of Portugal. Collected samples from a total of 150 herds, of which 129 (86.0%; 95% CI: 80.67% - 91.33%) had at least one seropositive animal. Out of 2607 individual blood samples, 1074 (41.2%) were positive for SRLV. The risk factors associated with SRLV infection were: specie (caprine), age (> 2 years old), herd size (> 100 animals), production system (intensive), production aptitude (milk), type of activity (professional), participation in livestock competitions (yes), buy replacement young ewe (yes) and rearing (natural). This knowledge empowers the implementation of effective preventive measures. Overall, biosecurity measures should be promoted and implemented to aim reducing viral transmission, with the main goal of reducing the prevalence of this disease. Completely, we understand that government authorities should promote and audit voluntary control and eradication programs in small ruminant herds in the region studied.