Hunters in areas with chronic wasting disease should take extra precautions, as the disease has been found in the heart muscle of some infected animals, as well as the brain, experts said Thursday.

But the Wyoming Game and Fish Department is still leaving it up to individuals as to whether they want to eat animals that have tested positive for the brain-wasting disease, despite public health agencies' recommendations not to eat infected animals.

Terry Kreeger, wildlife veterinarian with the Game and Fish Department, said Thursday his department is not going to recommend against consuming animals testing positive. The Centers for Disease Control and Prevention and the World Health Organization, meanwhile, recommend animals testing positive for chronic wasting disease not be consumed.

"Our position stays the same: It's up the individual," Kreeger said. "There's no proof that humans get it."

At the same time, he said the department may consider listing the heart as an organ not to eat, along with the brain and spinal column, in the agency's recommendations to hunters.

Researchers with the University of Wyoming, Game and Fish and the Colorado Division of Wildlife discovered chronic wasting agents in the heart muscle of white-tailed deer and elk, the university announced Thursday. The finding is important because the cardiac muscle is considered meat and is consumed by humans.

Previously, the prions causing the disease had only been identified in brain and spinal column tissue. A prion is a kind of protein, and cooking meat does not kill the agent.

Thursday's announcement comes as thousands of Wyoming hunters are in the field in pursuit of deer, elk and moose. It also comes just days after a Colorado State University researcher concluded that chronic wasting disease is transmitted through saliva and blood.

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 chronic wasting is unusual because, unlike its very hard-to-spread relatives, it seems to spread fairly easily from animal to animal.

The CSU researcher, microbiology professor Edward Hoover, had concluded that because the disease can be transmitted by blood - and blood can be found in virtually all organs and tissues - the prions could be present everywhere in an animal. He recommended that elk and deer be tested for the disease before they're consumed.

Kreeger agreed that it is likely the prions carrying the disease could be present throughout an infected animal.

Although researchers said humans are still not at known risk of contracting a version of disease, they said hunters should not kill or eat animals that appear sick, and wear long rubber or latex gloves when field dressing animals.

According to UW's Thursday announcement, the disease was not found in the heart muscle of mule deer. Jean Jewell, a research scientist in the UW Department of Veterinary Sciences, said that finding was significant, as the disease was not found in hearts of even mule deer that had the disease.

"Right now, I have no idea what the difference would be, since white tails and mule deer are so closely related," Jewell said."It's very intriguing, suggesting perhaps a difference in the cardiac nerve supply between the two deer species."

Researchers also said the discovery opens other possibilities for research, such as following the disease down the nervous system.

Chronic wasting has been discovered in wild deer and elk in 10 states. In Wyoming, the disease largely centers on the southeast. It has also been found as far north and west as Hot Springs and Washakie counties. Last month, an elk killed by a hunter in the Shirley Mountains northwest of Medicine Bow in southeastern Wyoming tested positive.

Environmental reporter Whitney Royster can be reached at (307) 734-0260 or at royster@tribcsp.com.