Serological Survey of Small Ruminant Lentivirus Infections in Free-Ranging Mouflon and Chamois in Slovenia

Simple Summary Small ruminant lentiviruses (SRLVs) are responsible for the worldwide diseases maedi-visna and caprine arthritis-encephalitis in sheep and goats and are also widespread in Slovenian sheep and goats. The infection is lifelong with chronic inflammatory lesions in various organ systems. Cross-species transmission of SRLV strains in sheep and goats is well documented, but there are few data on the ability of these viruses to infect wild ruminants. The objective of this study was to investigate whether SRLVs circulate among wild small ruminants in Slovenia. Thirty-eight serum samples from free-ranging chamois and European mouflon were tested for antibodies against SRLV. A total of 1 mouflon tested seropositive, whereas all samples from chamois were negative. Small ruminant lentiviruses (SRLVs) belong to the genus Lentivirus in the Retroviridae family, which are responsible for the diseases maedi-visna and caprine arthritis-encephalitis in sheep and goats worldwide and are also widespread in Slovenian sheep and goats. SRLVs cause lifelong infections with chronic inflammatory lesions in various organ systems. Cross-species transmission of SRLV strains in sheep and goats is well documented, but there are few data on the ability of these viruses to infect wild ruminants. The objective of this study was to investigate whether SRLVs circulate among wild small ruminants in Slovenia. During the 2017-2018 hunting season, a total of 38 blood samples were collected from free-ranging chamois (Rupicapra rupicapra) and European mouflon (Ovis ammon musimon). The serum samples were tested for antibodies against SRLV by enzyme-linked immunosorbent assay (ELISA). The serological tests revealed that of all tested mouflons, 1 animal (11.1%) was seropositive, while all samples from chamois were negative. Based on the results of this study and considering the results of previous studies in which SRLV infections were detected in mouflons with low seroprevalence, it is very likely that the detected seropositive animal was an incidental spillover host for SRLV. Although no seropositive samples were found in chamois, we cannot speculate on whether chamois may not be a host for SRLV infection because of the small sample size and the disadvantages of the ELISA assay used when applied to samples from chamois.