Attacking CWD

During their visit to Rocky Mountain National Park, visitors may see park staff actively checking deer populations to determine the prevalence of Chronic Wasting Disease (CWD) and to try to prevent its spread. Another "Fun Fact" discussed CWD and gave a very brief overview of this project. The project involves capturing deer and taking a small tissue sample (biopsy) from their tonsils for laboratory analysis. Deer are fitted with radio collars and released. Because CWD is invariably fatal and incurable, any animals found to have the disease are euthanized so they don't spread the disease to other animals. Once the project ends, the radio collars are removed.

How do you catch a wild deer and take a biopsy? Doe T6, captured on April 19, 2004 was darted about 9:00 in the morning behind the Beaver Meadows Visitor Center. It took about 10 minutes for T6 to become completely anesthetized. Because the chemical used for anesthesia prevents the animal from moving, but not from seeing or hearing, she was fitted with a blindfold (a modified stocking cap), and all essential communication was spoken very quietly. One person was assigned to monitor her vital signs - temperature, breathing, and heart rate, while other staff checked her general condition, collected a small amount of blood, administered antibiotics, and removed a previous ear tag. T6 had been checked for CWD in June of 2002. Staff then gently propped her mouth open and quickly took a small sample from her tonsils, added a new ear tag, and fitted her with a radio collar. After the work was completed, staff administered a drug to reverse the effects of the anesthesia and moved quietly away. In about 10 minutes T6 returned to her band. The entire event took less than 45 minutes.

Park deer do not seem to be seriously alarmed by this procedure. T6 was in a group of seven deer, two of whom had been previously tagged and tested. One of those two had been tested the week before. The band did not run away when she was darted or processed. While this work progressed, the remaining six deer browsed or rested about 50 yards away in plain sight.

While park staff would prefer not to have to capture wild deer and go through this process, evidence from other locations indicates that, left untreated, CWD could destroy deer populations. It is hoped that by finding CWD positive deer early and removing them from the population before they show outward signs of the disease, we can prevent them from spreading the disease to other nearby deer. Finally, because of additional research on material collected from these animals, we hope to help scientists find a quicker test for the disease that can be done in the field, and ultimately to find a vaccine against this terrible threat to our deer population.