In many areas of the world, there is are requirements for summer shelter to protect horses from heat and insects. However, access to shelter for horses kept completely outdoors during winter is commonly required. This study, conducted in Sweden, investigated horses’ daytime shelter-seeking behavior in relation to weather conditions and insect activity during the summer. 

Eight Warmblood riding horses had access to two shelters of different designs to test which shelter design was preferred by horses. In addition, rectal and skin temperatures and insect-defensive behaviors were recorded to determine if horses benefited from the shelter. 

The horses were kept alone in paddocks and had access to two shelter types—an open shelter with roof and uncovered sides, and a closed shelter with roof, wind nets on two sides and opaque plastic opposite the entrance. Weather conditions were recorded every 10 minutes. 

The number of insects were counted from insect traps placed inside and outside of each shelter. Behavior (shelter use, insect-defensive behavior, locomotion, grazing) was recorded at 5-minute intervals for three hours in both the morning and afternoon. Rectal and skin temperatures were measured at 8:00 a.m., noon and 4:00 p.m. 

Ambient temperature ranged from 61 to 77°F. 

Five horses preferred the closed shelter and were observed inside up to 2.5 hours continuously. The insect defensive behaviors (skin shiver and ear flick) were performed less frequently when horses were using the closed shelter, indicating that they were less disturbed by insects. 

Based on these results, horses did make use of shelters during the summer, even when weather conditions were moderate. A shelter with roof and covers on three sides was preferred over a shelter with roof only and can reduce insect defensive behavior. 

To read more about the research click here. 

For more information from the University of Minnesota Extension group please visit their website.