Semi-domesticated reindeer may face health threats from climate-driven species redistribution

Ms Ann Albihn

Reindeer herding is important for many northern societies in Russia and Scandinavia. The reindeer (Rangifer tarandus) is highly adapted to harsh environment and sensitive to environmental perturbations. Semi-domesticated reindeer are generally healthy but immunologically naïve for many new infectious diseases. Recently new diseases has been observed in new areas. Epidemiology of vector-borne diseases are dependent on many parameters, one is the abundance and density of certain arthropod vectors for transmission to new hosts and of disease reservoir species. Climate driven ecosystem changes may cause more beneficial habitats for such animals, e.g. by invasion of new plants used as feed. Recent northern expansion has been noticed for the common tick (Ixodes ricinus) and for the roe-deer (Capreolus capreolus), a reservoir. Infectious diseases may impair reindeer health, disrupt food security, reduce earnings and transmit zoonotic diseases between animals and humans. Concerning future health treats, lessons may be learned from disease outbreaks in reindeer populations at southern locations, e.g. mosquito-borne, zoonotic West Nile fever in Iowa, USA and tick-borne babesiosis in Scotland. Further on, novel epizootics on farm animals may also affect reindeer. In Europe the midget-borne blue tongue respective Schmallenberg viruses has recently inflicted cows and sheep.

Today, knowledge is missing for e.g. vector distribution, base-line data for many infectious diseases and reservoir animals e.g. rodents, in the north. Improved surveillance, e.g. to identify and focus on “hot spot” areas may enhance possibilities to recommend preventive health measures for reindeer, as vaccination, treatment against ticks, timing of seasonal migration and of slaughter.