Research strongly indicates that stabling and social isolation are chronic stressors which have a negative impact on horse welfare. However, horse owners often cite stress of herd living (issues with herd hierachy and paddock aggression) as similarly stressful experiences for the horse - in order to justify stabling.

As has been well documented, equine ulcers are a direct result of stress. For the stabled horse, being deprived of movement and social interaction, the results are in.

In a recent study conducted by the University of Stuttgart in 2022, horses' stress levels and immunocompetence (susceptibility to illness) were tested in the same group of horses in different living environments.

The Study

15 horses were divided into two groups and placed in a herd living environment in new paddocks of approximately 2 hectares each. They were then 'reset' in their original setting for 8 weeks before being moved into individual stabling.

The stables allowed sight and tactile contact through barred windows.

Samples were taken from each horse before, during and after each change in living conditions. Behavioural assessments were evenly distributed over various days & times of day.

Results

The results of the study showed that the relocation of the horses to stables led to acute stress-induced immune modulations. Whereas the changes to the group composition in the paddock did not. The immune modulations seen after stabling were also accompanied by occurences of disturbed and stereotypy related behaviours within one week.

The study was not able to distinguish whether the stress was a result of reduced grazing and/or movement or the removal of social interaction. However other studies have indicated that there is a strong effect of social isolation - as found when stabled horses are given solitary turnout with no social interaction, there is no decrease in stress responses.

Conclusion

The researches concluded that stabling of horses represents an intense stressor. It results in acute and lasting alterations to blood counts.

Therefore the results of the study strongly indicate that social isolation (stabling) is a chronic stressor which has negative impacts on the health and welfare of horses. Furthermore this study highlighted the advantage of group housing systems, in view of immunocompetence.

Hopefully these results will help horse owners ake improvement to their management practices in order to increase the health and welfare of domestic horses.