Tigers (Panthera tigris) have been classified by the IUCN as Endangered since their first assessment in 1986. Despite significant conservation investment this status remains unchanged, and in the last 20 years both the tiger’s range and population have declined by at least 50%. Recent investigations have found that the species could face a new threat. Research in the Russian Far East, led by the PI, found that canine distemper virus (CDV) is infecting wild tigers and, without appropriate mitigation strategies, is capable of threatening population survival. Despite anecdotal reports suggestive of clinically infected tigers in other range countries, the status of CDV infection in tiger populations outside Russia remains unknown. Measuring the seroprevalence of CDV neutralizing antibodies is an important first step in determining the potential threat that the virus represents to unstudied tiger populations. However, lack of appropriate testing protocols in tiger range countries, and restrictions on sample export are major constraints in assessing the presence of antibodies. This project seeks to address this by introducing virus neutralization assays to wildlife laboratories in four key tiger range states: Indonesia, Thailand, India and Nepal.