Treponeme-associated hoof disease (TAHD) presents a significant challenge for elk management in Washington. The Washington Department of Fish and Wildlife (WDFW) has conducted a series of studies to determine the scope and implications of TAHD on area elk herds. Studies include:
- Online reporting tool: Since 2012, WDFW has monitored the spread and distribution of TAHD through online public reports of elk showing signs of the disease in Washington. Although the department does not verify all of those accounts, public reporting has been a key tool for tracking the disease, especially outside known affected areas.
- Community science: In 2015, WDFW recruited more than 200 community scientists to estimate the prevalence and geographic distribution of TAHD in southwest Washington. Volunteers and staff conducted 175 road surveys covering more than 7,300 miles and documented approximately 2,600 elk among 283 groups. Results showed that the proportion of groups affected by TAHD was highest in Cowlitz, Wahkiakum, and western Lewis counties.
- Elk survival and productivity: In 2015, WDFW initiated a four-year study to quantify the impact of TAHD on survival rates, reproduction and recruitment in the Mount St. Helens elk herd. This study will help researchers understand how the disease progresses in individual animals. Preliminary results suggest that elk with TAHD enter winter months in poorer condition, have lower survival rates, and have reduced pregnancy rates. (See: October 2018 WDFW Project Update and Preliminary Results).
- Hunter questionnaire: Since 2016, WDFW uses hunter reporting to estimate the prevalence of TAHD in Washington. The number and proportion of hunters who report hoof abnormalities on their harvest is consistently highest in the Willapa and Mount St Helens elk populations of southwest Washington.
- Aerial elk surveys: In spring 2017, WDFW biologists flew a series of transects over more than 2,000 miles of southwest Washington to help gauge the prevalence of TAHD in area elk herds. Results were consistent with other efforts indicating the disease is most prevalent in Cowlitz, Wahkiakum, and the western half of Lewis counties.