Wood chewing not only damages stables and fencing, it can also be bad for the horse’s health. Wood splinters can get stuck in the gums or teeth. If swallowed, the splinters can damage the stomach or intestines, or cause impaction colic. Fortunately, the habit of wood chewing is usually not difficult to correct and the short-term health risks are low in most cases.
One first needs to check that the problem is wood chewing and not cribbing. Both activities are similar in that they involve the horse biting and damaging wood, but they are completely different problems. Wood chewing is exactly that; the horse chews on wood (e.g. in its stall or wooden fencing). With cribbing the horse does not chew on the wood but instead grabs it with its front teeth, then arches its neck and sucks in air. If you watch the horse, you can easily see which of the two problems it has, as the two activities are completely different. If you can’t catch the horse in the act, examination of the wood should tell you, as one needs to check if the wood has been nibbled away or simply bitten hard.
The most common cause of wood chewing is boredom. Horses which are left in their boxes most of the day with nothing to do simply do not have enough mental stimulation, so they start chewing on wood to occupy themselves. Another cause is stress or nervousness; just as some people chew their fingernails or pencils when they are stressed, a nervous horse confined to its box with nowhere to direct its nervous energy may start chewing on wood to distract itself. The third possible cause of wood chewing in nutritional deficiencies; if the horse’s food does not contain all the minerals they need they will start to chew on other items (such as wood or earth) in an attempt to obtain the missing minerals.
If one does not know which of these possible causes is the issue, one can simply address all three. Try to provide as much pasture time, exercise and other mental stimulation as possible so that the horse is not bored. Watch the horse to see possible sources of stress (such as bullying by another horse) and fix the problem. Put a mineral stone and salt lick in its box to address any mineral deficiencies in its normal diet.
These steps should result in a reduction in wood chewing. However, once the horse has the habit of chewing on wood, the habit will continue even after the reason for it is fixed. Consequently, one also needs to take steps to address the behavioral aspect in addition to the causes.
One does this by actively preventing the horse from chewing on wood. Putting a live fence wire on top of fencing rails will prevent chewing there. A metal strip on wood surfaces in the stall (e.g. stable door) will make chewing difficult. One can also use one of the speciality paints which have been developed to taste bad; simply paint these on the wood surfaces to discourage chewing. Note that such paints need to be redone every few weeks since the taste fades and that one should first check that any such paint has been veterinary approved.
One should make sure to address both the cause (e.g. boredom) and the behavior (e.g. with paint). Doing just one or the other is insufficient. If one fixes the cause but not the behavior, the habit is likely to continue, although to a lesser amount. If one prevents the behaviour (e.g. with paint) but does not address the underlying cause, the horse still has a problem and this may well lead to the development of a different behavioral problem. – 29953