Oct. 6, 2006 — Deer probably spread a brain-destroying illness called chronic wasting disease through their saliva, concludes a study that finally pins down a long-suspected culprit. The key was that Colorado researchers tested some special deer.
Chronic wasting disease is in the same family of fatal brain illnesses as mad cow disease and its human equivalent. There is no evidence that people have ever caught chronic wasting disease from infected deer or elk.
But CWD is unusual because, unlike its very hard-to-spread relatives, it seems to spread fairly easily from animal to animal.
Scientists were not sure how, primarily because studying large wild animals is a logistical nightmare. The sheer stress of researchers handling a deer caught in the wild could kill it.
Likewise, animals deliberately exposed to infections must be kept indoors so as not to spread disease, another stress for deer used to roaming.
So Colorado State University researcher Edward Hoover turned to fawns hand-raised indoors in Georgia, which has not experienced chronic wasting disease.
"This allows you to do this safely so the deer aren't freaking out," explained Hoover, who reported the first evidence of saliva's long-suspected role in Friday's edition of the journal Science. "These deer are calm and approachable."
Hoover took saliva from wild Colorado deer found dying of CWD, and squirted it into the mouths of three of the healthy tame deer - about 3 tablespoons worth.
Additional tame deer were exposed to blood, urine and feces from CWD-infected deer.
