Stress in Stalled Horses

Horses are herd animals, preferring to stay within sight of other horses and sometimes becoming nervous and agitated if they are separated from their group. Thus, it’s not surprising that results of a British study found higher levels of stress in horses that were stalled without the ability to see or hear other horses.

Researchers at Nottingham Trent University placed 16 horses in one of four situations: stalled individually without any contact with other horses; kept in individual stalls but able to see, hear, and touch other horses in adjoining stalls; stalled in pairs, with each pair able to see and hear other horses stalled nearby; and turned out in a paddock in four-horse groups. Horses were kept in a particular situation for five days and were then turned out in grassy paddocks for two days before being placed in the next situation.

During each treatment, stress levels were determined by video observation of behavior and also by analysis of fecal corticosterone. Researchers also recorded the temperature of each horse’s eye surface, as increasing eye temperature is thought to signify stress.

Horses housed individually and isolated from other horses became more difficult to handle, while horses in groups showed more natural behavior similar to that of free-ranging horses. Fecal corticosterone levels were higher as horses were kept in increasingly isolated housing. Eye temperature was significantly lower when horses were kept in groups.

The results suggest that isolating horses in stalls and preventing contact with other horses increases stress levels. The researchers stated, “Group housing provides horses with an environment where they are able to display natural behavior, and contact with other horses improves overall welfare.” They indicated that this suggestion could be also applied to other equines such as zebras kept in zoos.

For horses that must be stalled, for example during recovery from an injury, a dietary supplement containing vitamin B1 (thiamine), such as B-Quiet (available in Australia), may help to alleviate nervous behavior.