A serological screening for potential viral pathogens among semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Finland

Authors: TRYLAND, MORTEN - University Of Norway; Cunha, Cristina; FUCHS, BORIS - Western Norway University Of Applied Sciences; BREINES, EVA MARIE - University Of Norway; LI, HONG - Retired ARS Employee; JOKELAINEN, PIKKA - University Of Helsinki; LAAKSONEN, SAULI - University Of Helsinki

Submitted to: Acta veterinaria Scandinavica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2023
Publication Date: 2/22/2023
Citation: Tryland, M., Cunha, C.W., Fuchs, B., Breines, E., Li, H., Jokelainen, P., Laaksonen, S. 2023. A serological screening for potential viral pathogens among semi-domesticated Eurasian tundra reindeer (Rangifer tarandus tarandus) in Finland. Acta Veterinaria Scandinavica. 65. Article 8. https://doi.org/10.1186/s13028-023-00671-4.
DOI: https://doi.org/10.1186/s13028-023-00671-4

Interpretive Summary: Reindeer herding and husbandry is a traditional and important livelihood in Fennoscandia. The aim of this study was to investigate semi-domesticated reindeer for exposure to selected viral pathogens in Finland. Blood samples were collected from 596 reindeer (358 calves and 238 adult reindeer; September - November 2015) from nine reindeer slaughterhouses, representing most of the reindeer herding regions in Finland. Plasma samples were investigated for antibodies against known and potential reindeer viral pathogens by using enzyme linked immunosorbent assays (ELISA). The screening revealed that seroprevalence of alphaherpesvirus and gammaherpesvirus (malignant catarrhal fever virus group; MCFV) were 46.5% (range at slaughterhouse level 29-64%) and 29% (range 4-59%), respectively. Only four reindeer had detectable antibodies against Pestivirus, giving a seroprevalence of 0.7% (range 1.0-1.8%). No antibodies were detected against Bluetongue virus (BTV) or Schmallenbergvirus (SBV). Alphaherpesvirus and gammaherpesvirus (MCFV) are enzootic in the Finnish reindeer population, as in other semi-domesticated reindeer herds in Fennoscandia, whereas the exposure to Pestivirus is very low compared to findings in Norway and Sweden. The ongoing changes in the reindeer herding industry necessitate knowledge on reindeer health and diseases that may impact animal welfare and health of reindeer and the economy of the reindeer herding industry.

Technical Abstract: Background: Reindeer herding and husbandry is a traditional and important livelihood in Fennoscandia. Climatic changes and encroachment of reindeer pastures have led to changes in reindeer husbandry, increasing the extent of supplementary or full ration feeding. Methods: Blood samples were collected from 596 reindeer (358 calves and 238 adult reindeer; September - November 2015) from nine reindeer slaughterhouses, representing most of the reindeer herding regions in Finland. Plasma samples were investigated for antibodies against known and potential reindeer viral pathogens by using enzyme linked immunosorbent assays (ELISA). Results: The screening revealed that alphaherpesvirus and gammaherpesvirus (malignant catarrhal fever virus group; MCFV) were enzootic in the reindeer population, with a seroprevalence of 46.5% (range at slaughterhouse level 29-64%) and 29% (range 4-59%), respectively. Whereas the seroprevalence was significantly higher for alphaherpesvirus among adult reindeer as compared to calves, no age difference was revealed for antibodies against gammaherpesvirus. The seroprevalence in the northernmost region (Region 4) was significantly higher to alphaherpesvirus (56%) as compared to the southernmost region (36%), whereas the seroprevalence pattern for gammaherpesvirus was the opposite, with 8% in the north and 50% in the south. Only four reindeer had detectable antibodies against Pestivirus, giving a seroprevalence of 0.7% (range 1.0-1.8%). No antibodies were detected against Bluetongue virus (BTV) or Schmallenbergvirus (SBV). Conclusions: Alphaherpesvirus and gammaherpesvirus (MCFV) are enzootic in the Finnish reindeer population, as in other semi-domesticated reindeer herds in Fennoscandia, whereas the exposure to Pestivirus is very low compared to findings in Norway and Sweden. The ongoing changes in the reindeer herding industry necessitate knowledge on reindeer health and diseases that may impact animal welfare and health of reindeer and the economy of the reindeer herding industry.