Sometimes I wonder if my horses are part beaver! More than one evergreen pine, deciduous tree, lilac bush and burn pile has been chewed to splinters as if the horses are planning to construct a dam in the middle of the pasture. This is especially true with the two four year olds. They are turned out at least 8-12 hours each day where long stem forage is always available yet continue to naw on any post or rail not slathered in Cribox or covered in hot wire. Knowing full well that these horse's nutritional needs are being satisfied, I must assume that there are behavioral or even physical needs for this tree butchering. Wood chewing has long been observed as a destructive stable vice in horses, but can it be turned constructive to mitigate boredom? My mission this week was to reframe the research and/or discussion around wood chewing.
Wood chewing is terribly destructive to any equine facility. (And expensive too while lumber prices skyrocket!) I myself have brand new post and rail fencing, and the thought of teeth marks on any bit of it grates on my nerves. However, what if the answer to my problem is to embrace wood chewing as a common equine behavior rather than strategize for complete prevention? A recent guest lecture about enrichment opportunities for horses in confinement changed my problem solving trajectory. Alayne Blickle of Horses for Clean Water encouraged horse owners to provide non-toxic tree limbs and bushes as forms of entertainment for horses in confinement. I thought this was an excellent suggestion that seemed to point to a fundamental, if not essential, need for chewing.
First off, let's take a Google tour around the publicly available, peer-reviewed information on wood chewing. In my search for scientific inquiry, wood chewing came up surprisingly often especially in the management of racing horses. It was always framed as an unwanted stable vice. It was also surprising how common it really is across disciplines. The occurrence of wood chewing studied in Thoroughbred race horses, Standardbred race horses, eventers, dressage, endurance and pleasure horses consistently landed between 30-54% (Hanis et al., 2020; McGreevy et al., 1995; Waters et al., 2002)! That's 1 in 3 to 1 in 2 horses at any given modern horse facility. Stable vices such as wood chewing are not only ordinary, but have been around since horses were domesticated.