# Use of Leg-Mounted Monitors to Assess the Effects of Treponeme-Associated Hoof Disease on Elk (Cervus canadensis) Activity

## TL;DR

Researchers tested leg-mounted monitors on elk to detect changes in activity caused by hoof disease, showing potential for early disease monitoring in wild populations.

## Contribution

A new leg-mounted monitor was developed and validated for detecting TAHD-related activity changes in elk.

## Key findings

- The monitor accurately categorized elk activity with 85% overall accuracy.
- Elk with TAHD spent 10% more time bedded compared to controls during the challenge period.
- The monitor reliably detected reduced activity associated with mild TAHD lesions in captive elk.

## Abstract

Impacts from treponeme-associated hoof disease (TAHD) on individual elk and populations of free-ranging elk are of concern to interested publics and wildlife managers where the disease occurs in the northwestern United States. Lesions from TAHD range from minor skin ulcers on the feet to malformed and sloughed hoof capsules. Monitoring wild animals is challenging, and although lameness and debilitation may be observed in elk with severe lesions, the impacts of TAHD on elk activity throughout the disease course and in remote locations are difficult to determine. Remote monitoring of elk for changes in activity may provide a means for early detection and monitoring of impacts from TAHD. We evaluated a newly designed leg-mounted activity monitor that categorized activity as standing, moving, or bedded and remotely transmitted data to a receiver. We found that the monitor functioned reliably when placed on captive elk, accurately categorized their activity, and detected reductions in activity associated with mild TAHD lesions. Successful use in captive elk provides confidence for moving forward with further refinement of the system for deployment in free-ranging wildlife to evaluate impacts of TAHD and potentially other diseases.

Treponeme-associated hoof disease (TAHD) is an emerging disease of free-ranging elk (Cervus canadensis) in the northwestern United States. Affected elk develop chronic foot lesions, lameness, debilitation, and an apparent increase in mortality, but the onset of lameness and associated changes in activity are not fully understood. We evaluated the accuracy of a newly developed leg-mounted tri-axial accelerometer monitor (Advanced Telemetry Systems) on captive elk and collected monitor-derived data to assess activity before and during an experimental TAHD challenge. Monitors provided reliable data with 85% overall accuracy of the continuous onboard classification of activity as standing, moving, or bedded against direct visual observation using seven healthy elk. Further, following TAHD challenge, monitor-derived data were able to detect that treatment elk exhibiting abnormal locomotion spent more time bedded and less time moving or standing. During the challenge period, treatment elk spent roughly 10% more of the day bedded than control elk. These findings suggest that leg-mounted activity monitors can detect changes in elk activity and may serve as a useful tool for future wildlife disease monitoring efforts.