Horse walks into the bar, barman says why the long face?

Jun 23 2004

Ever wondered why horses have such long faces? A new study at The Nottingham Trent University has revealed that they may suffer from a form of Seasonal Affective Disorder – a type of depression that affects humans during the winter.

Seasonal Affective Disorder (SAD) is caused by a biochemical imbalance in the brain due to fewer daylight hours and a lack of sunlight. As well as feelings of depression, it can cause sleep problems, lethargy, overeating, anxiety and mood changes.

The study at Nottingham Trent’s Brackenhurst Equestrian Centre looked at the behaviour of a group of horses, half of which were given light treatment therapy, one of the most effective treatments for SAD in humans. A local company that produces these lights for human treatment wanted to find out whether horses could benefit too. The treatment involved the horses standing under specially designed light strips (Brite-boxes) for an hour a day for six weeks.

Horses are often kept stabled during the winter and consequently live for long periods in unnaturally dark conditions. Those taking part in the study were assessed on various aspects of their behaviour before and after the light treatment therapy. Their sleep and eating patterns were monitored, and they were scored on how they reacted to being handled and to being isolated from other horses, as well as how they performed when being ridden and jumped.

The results were recorded by students who did not know which horses had been exposed to light therapy and they showed a difference between the two groups.

Although those that had undergone light treatment therapy did not show much of a change in any of the behaviour that was tested, those that had not stood under the lights showed some signs of suffering from the winter blues. They slept for slightly longer than they had previously and were less enthusiastic about being ridden, as demonstrated by poorer performances when jumping. Those that had undergone the light therapy were reported by the yard manager as being less grumpy than they usually were at that time of year.

Carol Hall, Senior Lecturer in Equine Sports Science at Nottingham Trent, said: “We believe that these results go some way towards suggesting that light treatment results in happier horses that are easier to ride. The findings have indicated that horses may get depressed over the winter months and that treating them with light therapy could be effective in reducing these winter blues. By monitoring the horses’ behaviour during the summer it may be possible to select those that would particularly benefit from such treatment in the future.”