Elk hoof disease has continued to spread throughout southwest Washington and is now found in northwest Washington and across the Cascade Mountains into eastern Washington. The number of sightings of limping elk with deformed, broken, or missing hooves has increased dramatically since 2008. There is much that is not yet understood about the disease, including how the infection begins and how it is spread.
Hoof disease is a form of digital dermatitis, a condition that has plagued livestock for years that only recently (as of late 1990s) has been sighted in elk. Elk hoof disease causes severe overgrowth and deformity of elk hooves and is highly contagious among elk populations. The disease is caused by triponeme, a spirochete bacterium, and is limited to the hooves. It does not affect the rest of the elk and affected elk are still safe for human consumption.
Hoof lesions, Han, S. and K.G. Mansfield. 2014. Severe hoof disease in free-ranging Roosevelt elk (Cervus elaphus roosevelti) in southwestern Washington, USA. Journal of Wildlife Diseases, 50(2):259-270.
The WDFW maps indicate incidental observations throughout Washington state (red indicates sightings of limping elk and black indicates dead elk with deformities). The maps (January 2017 on the top and May 2018 on the bottom) show the continued spread of the disease through observed cases in just over a year.
WDFW Elk Map, 2017
WDFW Elk Map, 2018
In an attempt to learn more about the disease, wildlife managers from WDFW radio-collared more than 90 cow elk in the Mount St. Helens area and continue monitor the cows’ welfare. Research is mainly focused on the extent of the infection throughout the elk populations and how it affects elk survival and reproduction. Earlier this year, Washington State University received $3 million to continue the study of the disease over the next two years.
Elk hoof disease first appeared in the Cowlitz River basin in the late 1990s, and the number of cases increased sharply starting in 2008. The disease has spread throughout southwest Washington, infecting elk in 10 Washington counties, and continues to spread. In 2015, five elk in northwest Oregon tested positive for the disease; and in early 2016, the disease was documented in northwest Washington (Skagit County). Other than the diagnosis that was first completed for wild populations in 2014, there is not a lot of information available on the disease. It is unknown how the disease starts; therefore, current efforts focus on determining where each population is infected with the disease. There is no vaccine for the disease, and there are no options for treating it in the field.
Because the cause of the disease and how the disease is spread are poorly understood, it is especially important to thoroughly clean and decontaminate gear between uses. King County has prepared a great small gear decontamination protocol to prevent the spread of disease and invasive species. Remember to clean gear first with soap and water to remove all organic debris before applying decontamination solution (2% Virkon Aquatic solution is WDFW’s preferred solution).
