SANTA FE (AP) – New Mexico wildlife managers are using a new method of testing for chronic wasting disease that allows them to gather samples without killing the animals.

The recent discovery at Colorado State University that the disease can be detected in the animals’ lymph nodes led to the change.

Wildlife officers performed tonsillectomies on three mule deer last week. All three survived the operation.

“We’re only the second state in the nation to be doing it,” said Martin Frentzel, spokesman for the state Department of Game and Fish. “This process is just now hitting the scientific journals. It really is groundbreaking.”

Each procedure was performed at an outside operating station and took about 20 minutes.

Blindfolded and hobbled, the tranquilized deer were brought to the station, where they are given an antibiotic. A vise holds the deer’s mouth open while a veterinarian reaches down its throat with a device and removes small pieces of a tonsil. The deer is then given a blood test and is fitted with radio collars and ear tags.

“The deer is sleeping basically, and we monitor its temperature and its heart rate,” said Patrick Morrow, wildlife biologist for White Sands Missile Range Morrow. “All of the deer that we handled, we didn’t have any mortalities, and they all responded just perfectly.”

The sedated deer were taken to a secluded place where they slept off the medication for about an hour before they got back on their feet. Officers then tracked and observed the deer for a day or two.

“Within a day, they’re ready to eat again,” said wildlife health specialist Kerry Mower of the Game and Fish Department. “There will still be some pain in their throats, but it wasn’t hindering their eating at all. We were very satisfied with that.”

The samples were sent to CSU’s chronic wasting disease diagnostic laboratory for testing. Officials said it will take several weeks before the results are returned.

If any of the test results come back positive, the deer will be tracked and killed, officials said.

Once found only in small areas of Colorado and Wyoming, chronic wasting disease has spread to elk ranches and wild deer herds as far away as Wisconsin. New Mexico’s first and only case of the disease was detected in a sick mule deer killed March 28 at White Sands Missile Range.

Chronic wasting disease creates sponge-like holes in a deer’s brain, causing the animal to grow thin, act abnormal and die. The disease is similar to mad cow disease.

There has never been a known case of it being transferred to humans or livestock.

The state Department of Game and Fish is conducting the tests with the U.S. Army, U.S. Department of Agriculture, CSU and other agencies.

Because it takes more time and personnel to perform the live tests, “it’s very costly to do the operation we’re doing,” Morrow said. “Killing is the easier, quicker, more realistic way to get the number of samples you need, but we don’t have those numbers down here.”

Larry Bell, director of the New Mexico Department of Game and Fish, wanted to attempt the live tests rather than eradicate the state’s already depleted deer herds.

“Unless we have to, we don’t want to go in there and whack a bunch of deer,” Frentzel said.

Like many states in the West, New Mexico has a mule-deer population that is currently lower than it has been for decades. Most biologists agree the decline can be blamed on drought, increased predation and poor habitat.