Chronic Wasting Disease (CWD) is a fatal prion disease affecting cervids (deer, elk, moose) in North America and Scandinavia. The disease causes progressive neurodegeneration over 12-18 months, with affected animals showing emaciation, behavioural changes, excessive salivation, and loss of fear of humans before death. No treatment or vaccine exists. CWD prevalence has expanded to 31 US states and several Canadian provinces; Norway confirmed European cases in wild reindeer. Welfare implications are profound: CWD causes prolonged suffering over the disease course. Management responses include targeted culling to reduce transmission, movement restrictions on deer transport, mandatory surveillance, and hunter education. The welfare ethics of CWD management involve trade-offs between lethal control of apparently healthy deer to prevent disease spread versus allowing natural disease progression. Prion persistence in the environment complicates control; CWD has zoonotic potential requiring ongoing monitoring.