Chewing rails, feeders and doors is a common habit in horses confined to stables and yards when fed mainly on concentrate diets. Horses at pasture will occasionally chew rails and trees, particularly during wet or cold weather.

Many horses will chew and may ring bark young trees in early spring, presumably because the sweet juicy sap is flowing, or pasture is lush and succulent with a lower fibre content. It is also possible that the high soluble starch intake on lush pasture leads to a hindgut overload and fermentation with acid production, which irritates the gut, causing the horse to seek fibre to eat.

Most horses prefer to chew soft woods, including treated pine rails, plywood and particleboard. Observations indicate that a stabled horse spends an average of 8 minutes per day chewing stall fixtures. Although most of the wood chewed is not swallowed, splinters of wood may lodge between the teeth or lacerate the gums or tongue.

Wood chewing also wears away the front edges of the upper and lower incisor teeth. A horse confined to an outside steel fenced yard may develop a habit of licking the pipes, wearing off the paint and exposing the metal, which then rusts.

Causes of chewing habits

Some authorities consider a lack of phosphorous, fibre or protein in the diet may result in an urge to eat wood. Feeding a low-fibre pellet or sweet-feed based ration also increases the risk in a stabled horse. In this case, less chewing is required to consume the smaller meal, which is quickly eaten, leaving more leisure time for the horse to become bored between feeds.

Remedies for chewing habits

  • Reduce boredom by providing good quality hay between meals, particularly overnight
  • Hang a couple of 'play toys', such as a large rubber soccer ball on a rope or a plastic drink bottle, above the door opening or in a corner
  • Provide stabled horses with regular exercise or outdoor free activity in a yard or paddock
  • Dilute pelleted rations with an equal amount of chaff to increase bulk and extend feeding time
  • Add a mineral supplement such as Feramo-H to correct any mineral deficiencies
  • Adding a standard dose of the product Founderguard, which modifies hindgut fermentation to reduce acid build-up, to concentrate rations has been observed to significantly reduce the incidence of wood chewing in both pastured and stabled horses
  • Replacing soft wood rails with hard wood may deter some nibblers, and covering ledges and door tops with metal strips may reduce damage
  • Strands of charged electric fence wiring fixed over problem areas may help, but bad cases will be forced to chew elsewhere, or develop other boredom-related vices
  • Coating rails, tops of fence posts, door tops, ledges, and even exposed roots and trunks of trees with a thin layer of Stop Crib paste can also deter chewing habits. Stop Crib lasts for 30 days or longer on internal rails or doors, and for 2–3 weeks on surfaces exposed to rain and hot weather