Traditional Knowledge (TK) is increasingly valued in long-term monitoring of wildlife health, particularly in northern Canada where Chronic Wasting Disease (CWD) may represent a threat to valued caribou and moose populations. This article presents comparative research results (1998–2002 and 2010) about caribou and moose health based on research with Łutsël K’é First Nation, Northwest Territories (Canada). Elders’ knowledge, harvester observations, harvest data and consumption data indicate a decline in the availability of barren ground caribou and range shifts of both caribou and moose during the study period. An anomalous sighting of a white tailed deer near the community, coupled with moderate community concerns about CWD would suggest the need for greater monitoring of wildlife health. As resources for scientific monitoring become limited, the article suggests how northern Indigenous communities can use their own knowledge (TK) to monitor changes in arctic ecosystems.