Alberta’s first documented case of CWD in a moose was confirmed in January 2013
Posted Feb 14 2013 4:52pm
Chronic Wasting Disease
Alberta’s first documented case of CWD in a moose was confirmed in January 2013.
An adult male moose that collided with a vehicle in the CWD risk area in eastern Alberta was submitted for disease testing. This moose was confirmed to have prion changes in the brain consistent with CWD infection.
Chronic Wasting Disease (CWD) involves fatal damage to the brain in members of the deer family, including:
In Alberta, CWD has been found in the wild in mule deer, white-tailed deer and on moose. Alberta’s CWD management strategy depends on hunter assistance to help track CWD infections.
Herds infected with Chronic Wasting Disease in Canada in 2013
The CFIA works with provincial governments and industry to conduct regular Chronic Wasting Disease (CWD) surveillance. Ongoing provincial surveillance for CWD varies with each particular province's perceived threat and infection status. Testing is mandatory in Manitoba, Saskatchewan, Alberta and the Yukon; it is voluntary elsewhere.
In addition, CWD is a reportable disease under the Health of Animals Regulations. This means that all suspected cases must be reported to the CFIA.
The following table lists domestic cervid herds confirmed to be infected with CWD in Canada in 2013.
Current as of: 2013-01-31
Date confirmed Location Animal type infected January 30 Saskatchewan Deer
Three captive Shira’s moose (Alces alces shirasi) were orally inoculated with a single dose (5 g) of whole-brain homogenate prepared from chronic wasting disease (CWD)–affected mule deer (Odocoileus hemionus). All moose died of causes thought to be other than CWD. Histologic examination of one female moose dying 465 days postinoculation revealed spongiform change in the neuropil, typical of transmissible spongiform encephalopathy. Immunohistochemistry staining for the proteinase-resistant isoform of the prion protein was observed in multiple lymphoid and nervous tissues. Western blot and enzyme-linked immunosorbent assays provided additional confirmation of CWD. These results represent the first report of experimental CWD in moose.
It is unknown whether moose can die from PrPCWD infection and whether CWD presents a threat to free-ranging moose populations. Nonetheless, this experiment did confirm that 1) moose can become orally infected with mule deer–derived CWD, 2) PrPCWD propagated and accumulated in multiple lymphoid and nervous tissues similar to deer and elk (Spraker et al., 1997), and 3) PrPCWD caused spongiform changes in the central nervous system considered characteristic for CWD in cervids (Williams and Young, 1992). Thus, this is the first report of experimental CWD in moose.
Subsequent to these findings, a hunter-killed wild moose was diagnosed with CWD in Colorado in September 2005 (M. Miller, unpubl. data). Although CWD has now been established in moose, cases in moose probably will be a rare occurrence because their social habits differ from elk and deer. Nonetheless, wildlife managers should be aware of this possibility and increase their surveillance efforts for naturally occurring CWD in moose.