Chewing rails, feeders, doors, and trees is another habit brought on by boredom and confinement with infrequent or irregular meal times. Many horses like to chew soft woods, particularly sweet cedars and even treated pine. Observations indicate that stables horses spend an average of 8 minutes per day chewing stall fixtures. Splinters of wood and nails ect. may lodge between the teeth or lacerate the gums or tongue. Some horses confined to outside steel fenced corrals develop a habit of licking pipes, wearing off the paint and exposing the metal which rusts.
Some authorities consider a lack of phosphorous in the diet may result in an urge to eat wood. Sweet feed based diets also tend to increase the habit. Confining a horse to a barn by itself increases insecurity and boredom. Feeding of pelleted rations also increases the risk, possibly due to the low volume ration and boredom between feeds.
Provide a balanced ration with a calcium/phosphorus ratio of 2:1. Up to 10% bran to provide extra phosphorous may be added to high alfalfa-roughage based rations. Reduce boredom by providing good quality hay between meals, particularly overnight. Replacing soft wood rails with hard lumber deters some nibbles, or covering ledges and door tops with metal strips may reduce damage. Strands of charged electric fence wiring over problem areas may help, but bad cases will be forced to chew elsewhere. Coating rails, door tops and trees with hot, bitter tasting preparations to deter chewing is also worth trying. Dilute pelleted rations with an equal amount of chopped hay to increase bulk and extend feeding time.