According to the Washington Department of Fish and Wildlife, there is no scientific evidence that chemicals can cause this kind of disease in animals, and no link has been made between herbicides and hoof disease in any species that we are aware of. Timber companies use similar herbicide treatments all along the West Coast, yet elk populations in other areas have not exhibited the symptoms associated with hoof disease seen in southwest Washington.
Ongoing research with exclosures conducted on managed timber land indicates that timber management, including the use of herbicides, increases the variety of quality browse vegetation for elk and deer, and even increases the variety of bird habitat!
Generally, one or two herbicide applications are made during the first few years of a 40 year rotation cycle. Depending on the product being used, a few ounces to a few quarts of herbicide are applied per acre. The herbicide is mixed with water prior to application to ensure even coverage.
Timber is not harvested near streams or in wetlands so these areas are never sprayed. If there is surface water present at the time of an application, existing rules require a buffer zone around it.