Three more New Mexico mule deer have tested positive for deadly chronic wasting disease. State Game and Fish Department officials said today that all three infected deer were from the White Sands Missile Range in southern New Mexico, the site where the only other state deer to test positive for the disease was found.
Chronic wasting disease is a neurological disorder transmissible among deer and elk and always fatal to those animals.
So far, only four deer have tested positive for the disease out of 557 New Mexico deer and elk whose tissue has been examined by a laboratory at Colorado State University in Fort Collins.
But what’s surprising is that four of the 15 deer samples collected at White Sands were infected with the disease, a rate of more than 25 percent.
Game and Fish Department spokesman Marty Frentzel said that in Colorado, the percentage of diseased deer in an infected area varies from less than 1 percent to a range between 3 and 15 percent.
“Of course, the fact that we have more than 25 percent at White Sands may just be due to the small number we’ve tested there,” Frentzel said. Even so, the test results are not good news for the White Sands deer population.
“With an incubation period between 18 months and five years, the prevalence rate we are detecting at White Sands suggests CWD has been present there for a number of years,” said Kerry Mower, a wildlife disease specialist with Game and Fish.
Larry Bell, director of Game and Fish, conceded there appears to be a wasting disease problem at White Sands.
“But overall, our testing indicates this disease is not widespread in the state,” Bell said. “We will continue to monitor the situation to the best of our ability.”
After the disease was discovered in the first White Sands deer back in June, Bell declared a state animal health emergency and barred the importation of deer or elk. That ban is still in effect.
Another 59 samples of deer and elk tissue collected in New Mexico remain to be tested by the Colorado State Veterinary Diagnostic Laboratory. These include seven samples taken by hunters during a January hunt in the Organ Mountains adjacent to White Sands Missile Range. Some hunters have been cooperating with the state by bringing in tissue samples from the deer and elk they have killed. But the four animals that tested positive were collected by state officials.
Of the three most recent deer to test positive, one was tested in December at White Sands using a tonsil biopsy technique that permits tissue to be taken without killing the animal. This deer was killed after it tested positive for the disease.
The other two were tested by the more conventional method in which the animal is killed and its brain stem removed for examination.
Mower said the state will continue both live and lethal testing and expects to collect as many as 100 additional samples between now and June.
“Between now and when things start to green up in May, there is so little nutrition we begin to see sick animals, which we will collect,” Mower said.
He said that until sick animals are tested, it is impossible to know whether they are infected with CWD or suffering from malnutrition or some other malady. CWD symptoms include weight loss, lethargy, staggering, excessive salivation and drinking water more than is normal.
The disease is not known to be contracted by humans, but the state has advised hunters to use latex gloves while dressing animals and to avoid eating nervous-system tissue such as brains, spinal cords, lymph nodes and eyes.
Mower is in Laramie, Wyo., this week attending a multistate conference designed to coordinate regulations aimed at controlling the disease.
He said New Mexico is not sure how the disease got to White Sands. Although the disease was first detected in New Mexico last year, it has been studied for three decades in northeastern Colorado and southwestern Wyoming.
More recently, it has been found in either wild or captive deer and elk herds in Illinois, Kansas, Minnesota, Montana, Nebraska, Oklahoma, South Dakota, Wisconsin and in the Canadian provinces of Alberta and Saskatchewan.