Hmmm, all I could find about moose and bison was this from the United States Animal Health Association. "Oral transmission is considered the primary natural route of transmission of CWD as for the other TSEs of animals...Species Exposed: A wide variety of species, from rodents such as deer mice (Peromyscus maniculatus) to moose (Alces alces), have been exposed to CWD agent in endemic facilities and have not developed CWD. This includes ruminants such as domestic goats, sheep, and cattle, pronghorn antelope (Antilocapra americana), bighorn sheep (Ovis canadensis), bison (Bison bison), mountain goats (Oreamnos americanus), and moose. The number of individuals of each of these species is relatively small; however, these uncontrolled observations suggest that these species are, at least, not as susceptible as the cervids to the CWD agent."