CSU Rushing To Create Live Test for CWD

August 7, 2002
By Jennifer Mooney, Special to The Denver Post

Researchers at Colorado State University are scrambling to find a live test for chronic wasting disease in deer and elk, but significant obstacles still stand in the way.

A tonsil test developed by the Colorado Division of Wildlife remains the only way to test a living animal for the fatal brain disease, found in wild deer and elk herds. A live test would be vital for the survival of the ranched elk industry, which has suffered since an outbreak of CWD in Colorado last year.

"If I could test my own herd, I'd take away the positive animals and minimize the exposure time they had with the rest of the herd," said Colorado elk farmer Dave Whittlesey. His meat sales have plummeted since consumers have become more informed on CWD.

At Tuesday's national chronic wasting disease symposium in Denver, experts discussed the only validated method of live testing on deer - tonsil biopsies.

Doctors at Colorado State University are trying to perfect a simpler and more efficient method that would test the animal's urine or blood.

The unknowns about the disease - which eats holes in the brains of deer and elk, causing them to lose weight, become disoriented and die - continue to create obstacles for researchers studying different live testing methods.

"We're a bit limited by the biology of the disease," said Katherine O'Rourke, a research microbiologist for the U.S. Department of Agriculture.

"In 2002, we are certainly going to see some diagnostic problems along the way, but 2003 is going to be a piece of cake," she said, referring to private companies that are developing CWD live tests.

Information on such tests is typically not released until the product is licensed and marketed, O'Rourke said.

The most widespread method of determining whether an animal has the disease is to decapitate it and study portions of its brain and lymph nodes.

The tonsil biopsies are currently being used in a few areas of Colorado to test CWD's prevalence where hunting is not allowed, such as near Estes Park and Livermore.

Dr. Lisa Wolfe, a wildlife veterinarian with the Colorado Department of Wildlife, is running a tonsil biopsy study on live deer at risk for CWD. The deer is sedated and a gag is placed in its mouth. A specially trained person inserts a biopsy tool into the deer's mouth to collect a specimen from the animal's tonsils.

But getting a perfect sample is not that easy, said Wolfe, who has taken 400 tonsil biopsies.

"It's not an ideal test, but it is a live animal test that works real well," she said. "It's reliable and fairly inexpensive."

So far, elk are not eligible for any live testing.

Representatives from CSU are working on alternative methods of live testing. Whether CSU's tests will be successful and made available to the public is still unknown, said Todd Malmsbury, spokesman for the Colorado Division of Wildlife.

"It would be a huge step," he said. "We wouldn't have to kill all the animals if only one tested positive."

Activists from national animal-rights groups, as well as residents who live in the areas where large numbers of deer and elk are being killed, hope live testing will become more prevalent nationwide.
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