Environmental Enrichment Study

The effect of hay net position on box-walking

A simple experiment was performed using an 18 year old Thoroughbred mare.  The owner of the horse had expressed concern over the amount of time the horse spent pacing, or box-walking.  The owner finds it difficult to put and keep weight on the horse, although it is accepted that Thoroughbred horses are naturally thin.  The horse is currently turned out for approx 10 hours per day, and stabled at night with ad-lib hay provided.

The horse was observed on two separate occasions to establish the extent of the problem.  The horse was observed twice more after the complete removal of the hay-net from the stable.  Two further observations were undertaken after repositioning the hay-net at the front of the stable, beside the door.  The observations were taken through the window of an adjacent building, approximately 10 metres distance from the stable.

It was found that under normal circumstances, the horse spent 78.3% of the 30 minute observation box-walking.  Removing the hay-net reduced the time spent box-walking by 25%.  Repositioning the hay-net by the stable door further reduced normal box-walking behaviour by 57%.

It appears that with this particular horse, the motivating factor for box-walking was to access the hay-net at the rear of the stable, and return immediately to the stable door.  This is more likely to be due to poor stable design, rather than the true existence of a behavioural problem. This conclusion was reached based on the management of the horse; the horse receives regular turn-out with others, and is given access to sufficient forage, both are factors known to prevent stereotypies.

The subject of this experiment was an 18 year old Thoroughbred mare, the owner of the horse had expressed concern over the amount of time spent pacing, or box-walking.  This article reviews what is currently known of box-walking and discusses new methods to prevent the development of this problem.

Stabled horses often exhibit behaviours which owners regard as unwelcome; these include stereotypies, defined as repetitive and functionless behaviour (McGreevy et al. 1995).  Such compulsive behaviours appear abnormal because they seem to be performed in an inappropriate context and because their motor movements and intensity often seem exaggerated (Luescher et al. 1998).

Surveys of stabled horses in the UK have indicated that over 15% of domesticated horses and 20-35% of racehorses show some form of behavioural abnormality.  Many of these behaviours are undesirable because they can influence the horse’s health and inhibit performance (Waran & Henderson, 1988).

Behavioural problems in horses are thought to relate to management practices (Houpt 1981, cited Luescher et al. 1998).  Confinement, isolation from social contact, restricted access to grazing areas and lack of environmental stimulation may all be factors that lead to the development of stereotypies in horses (Waran & Henderson, 1988). Spatial restriction, reduced feeding time due to provision of concentrated feed and lack of exercise are also factors thought to predispose an animal for compulsive behaviour (Kiley-Worthington 1983, cited Luescher et al. 1998).