Chronic wasting disease (CWD) is spreading through North American elk and deer populations, causing a fatal neurological illness in individual animals and challenging wildlife managers to respond humanely and effectively.
CWD creates prolonged, progressive suffering in individual elk over months. Early infection is asymptomatic, but as the disease progresses, affected animals experience dramatic weight loss (hence 'wasting'), neurological dysfunction causing stumbling and disorientation, behavioral changes including loss of fear, and eventual inability to eat or drink. The terminal phase before death involves severe debilitation. Unlike most wildlife diseases, CWD does not cause rapid death - affected animals can suffer for months. The environmental persistence of CWD prions means that contaminated habitats continue to infect new individuals for years after initial exposure. The welfare cost of the ongoing spread is measured in millions of individual animals experiencing this slow, distressing decline.