Influence of full-time housing in vector-protected facilities on equine cortisol levels, heart rate, and behavior during the African horse sickness outbreak in Thailand.

This study investigates how housing horses in certain types of barns, specifically vector-protected facilities, during a disease outbreak can influence their stress levels. They found that these facilities may contribute to higher stress, evidenced by changes in behavior, heart rate, and cortisol levels.

Research Background

• The research was conducted during an outbreak of African horse sickness (AHS) in Thailand. AHS is a highly infectious and deadly viral disease affecting horses.
• Due to the nature of the disease, horses were housed in vector-protected facilities, designed to protect them from the disease-carrying insects.
• The researchers sought to understand how this sudden change to an unfamiliar environment impact the horses’ stress levels and overall wellbeing.

Methodology

• Nine healthy horses were chosen for the study and housed in both traditional and vector-protected barns.
• Behavior and stress response data were collected in conjunction with the housing environments and various times of day. This included heart rate, blood cortisol levels, and behavioral scores based off specific actions.

Findings

• The researchers found that horses in the vector-protected barn exhibited a lower behavioral score at night compared to during the day, suggesting the unfamiliar environment was causing stress.
• The horses’ heart rate was on average lower at night, but this was true regardless of which barn they were in. This suggests that it’s a normal resting behaviour for horses.
• Blood cortisol, a stress hormone, peaked at 6:00 AM and was lowest at 6:00 PM in both environments and correlated with fluctuations in humidity and temperature.
• Interestingly, horses in the traditional barn showed earlier drops in cortisol levels compared to those in the vector-protected barn, suggesting that the vector-protected facilities were causing increased levels of stress.

Conclusion

• The results of this study indicate that housing horses in vector-protected facilities during a disease outbreak, like AHS, can contribute to increased stress levels.
• While these facilities are designed to protect horses from disease-carrying insects, they may introduce new stress factors due to their unfamiliarity or environmental conditions.