Effect of Exercise in a Vector-Protected Arena for Preventing African Horse Sickness Transmission on Physiological, Biochemical, and Behavioral Variables of Horses.

The research described in this article investigates physiological, biochemical, and behavioral responses to exercise in horses in different environments—a traditional open-air arena, and a net-covered, vector-protected arena, designed to protect them from African horse sickness transmission during an outbreak.

Methodology

• The researchers conducted a cross-over study using eight horses.
• Each horse was required to perform a 39-minute aerobic exercise in both a conventional arena (CA) and a vector-protected arena (VPA) at separate times.
• During and after the exercise, scientists recorded the horses’ rates of speed, the distances they covered, their cortisol release, hematology, and heart rate variability (HRV). This allowed the researchers to directly compare the impacts of the two different environments on the horses.

Results

• Horses in the VPA arena were generally slower and covered less distance than those in the CA arena.
• Cortisol concentrations, which signify stress, increased during exercise in both arenas, and remained high for 30 minutes after exercise.
• Hematocrit, hemoglobin, and red blood cell count increased immediately after exercise in VPA and remained high until 60 minutes postexercise in CA. These indicators are associated with increased physical activity and the body’s ability to transport oxygen.
• There was a discernable interaction between the riding arena type and time in relation to the hematocrit, hemoglobin, and red blood cell count.
• HRV, which relates to the stability of the horse’s heart rate, decreased during exercise in all arenas. However, it was found that there was a higher RR interval and Parasympathetic Nervous System (PNS) index, together indicating a lower heart rate and Sympathetic Nervous System (SNS) index, during the 30 to 60 minutes after exercise in horses in the VPA, compared to the CA.

Conclusions

• The study concluded that the type of horse riding arena affected the hematological and HRV variables of exercising horses.
• The greater RR intervals and PNS index observed in horses exercising in the VPA, along with the lower SNS index and heart rate, suggest a dominance of the parasympathetic nervous system post-exercise in these horses compared to those in the CA.
• This may signify that horses are less stressed in the VPA compared to the CA, suggesting potential benefits to exercising horses in vector-protected arenas during African horse sickness outbreaks.