Stress responses of horses during a long period of transport in a commercial truck.

This research article examines stress and dehydration patterns in horses transported over long distances in warm weather. It particularly evaluates effectiveness of various measures in identifying stress and dehydration in transported horses.

Research Methodology

• The study was conducted in a prospective manner where a group of 30 healthy, mature horses were put into four treatment categories.
• The categories included: horses that were kept in pens and offered water every five hours (5 horses), horses penned but not offered water (5 horses), horses transported with the provision to drink water every five hours (10 horses), and horses that were transported without any water offer (10 horses).
• After a duration of six hours of water deprivation, the study commenced.
• The transport vehicle returned to the pen every four hours. During this time, they weighed the horses, conducted physical examinations on them, and took blood samples. Some horses were also given water, depending on their treatment group.

Observations & Findings

• The study found that after being transported for 24 hours, three horses were adjudged unfit to continue and the study was then terminated.
• The horses that were kept in pens and had access to water every five hours drank 38.2 liters on average. In contrast, the horses that were transported and given access to water drank just 20.9 liters. Some of these horses did not drink until after 19 or 24 hours of transport.
• For horses that were either transported or penned without being offered water, the serum electrolyte concentrations exceeded the reference range values by 19 hours.
• The majority of horses transported with the option to drink water managed to consume adequate water to prevent severe dehydration for more than 24 hours.

Conclusions

• Domesticated, well-conditioned horses initially cut off from water for around six hours can withstand transportation in groups under high temperature and humidity for up to 24 hours before they start showing signs of severe dehydration and fatigue.
• The research concluded that the most useful measures to identify crisis situations in horses during transportation were rectal temperature and appearance.