Chronic wasting disease (
CWD) is a
transmissible spongiform encephalopathy (TSE) of
mule deer,
white-tailed deer,
elk (or "wapiti"), and
moose ("elk" in Europe). To date, CWD has only been found in
members of the deer family. First recognized as a clinical "wasting" syndrome in 1967 in mule deer in a wildlife research facility in northern
Colorado,
USA, it was identified as a TSE in 1978 and has spread to free-ranging and captive populations in 23 US states and two Canadian provinces. CWD is typified by chronic weight loss leading to death. No relationship is known between CWD and any other TSE of animals or people.