Chronic Wasting Disease of Captive Mule Deer: A Spongiform Encephalopathy

Abstract

In the past 12 years (1967-79) a syndrome we identify as chronic wasting disease has been observed in 53 mule deer (Odocoileus hemionus hemionus) and one black-tailed deer (Odocoileus hemionus columbianus) held in captivity in several wildlife facilities in Colorado and more recently in Wyoming. Clinical signs were seen in adult deer and included behavioral alterations, progressive weight loss and death in 2 weeks to 8 months. Gross necropsy findings included emaciation and excess rumen fluid admixed with sand and gravel. Consistent histopathologic change was limited to the central nervous system and characterized by widespread spongiform transformation of the neuropil, single or multiple intracytoplasmic vacuoles in neuronalperikaryons and intense astrocytic hypertrophy and hyperplasia. Presented is a clinical characterization of chronic wasting disease and pathologic evidence supporting the conclusion that the disease is a specific spontaneously occurring form of spongiform encephalopathy. mouflon (Ovis musimon).

A prion disease of cervids: Chronic wasting disease

“…Therefore, the capacity for CWD to cross species barriers has been of great interest. Until recently, natural CWD infections were believed to infect only white-tailed deer, mule deer, and Rocky Mountain elk [89,90,92]. This ended in 2006, when a report indicated that Shira's moose could be orally-infected with brain homogenate from CWD-infected mule deer, and shortly thereafter a natural case of a CWD-infected moose was discovered [4,42].…”

“…Only one study has been performed on cervid susceptibility to sheep scrapie by the ic route, and showed that 3 of 6 elk developed neurologic signs, spongiform encephalopathy and PrP Sc in brain [25]. Further experiments to address this question may be interesting since sheep scrapie is considered a possible source for CWD in North America [89,91].…”

“…Chronic wasting disease (CWD) is a prion disease of mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginianus), Rocky Mountain elk (Cervus ela-PrP C , which leads to neurodegeneration and ultimately death. In 1978, CWD was first recognized as a new TSE of captive mule deer in Colorado by pathologists Williams and Young [89]. Soon thereafter, a prion disease was reported in elk in Wyoming [90].…”

Influence of the geographic distribution of prion protein gene sequence variation on patterns of chronic wasting disease spread in white-tailed deer (Odocoileus virginianus)

“…CWD was first detected in cervids in the late 1960s in Colorado [2,3] and has since spread to an increasing number of other US states and Canadian provinces [4,5]. The disease is transmitted horizontally by contact with pathogenic prions shed in bodily fluids [6,7] and vertically from mother to offspring [8,9].…”

Epidemiology of Chronic Wasting Disease in Free-Ranging Mule Deer: Spatial, Temporal, and Demographic Influences on Observed Prevalence Patterns

“…and wapiti (Cervus elaphus nelsoni), has emerged as an important wildlife health problem in several parts of North America Williams et al, 2002). Epidemics of CWD appear to be self-sustaining, with transmission likely occurring in both the presence and absence of live, infected animals and infectious agents persisting in contaminated environments (Williams and Young, 1992;Miller et al, 1998Miller et al, , 2000Miller et al, , 2004Williams and Miller, 2002;Miller and Williams, 2003;Miller and Wild, 2004).…”