Horses are transported often, and sometimes over very long distances – to competitions, for breeding, at a change of owner, or to slaughter.
Horses are transported often, and sometimes over very long distances – to competitions, for breeding, at a change of owner, or to slaughter. Although it is a routine part of keeping horses, the research consistently shows that transport can be a significant physiological stressor, with consequences for the horse's health and welfare.
A study comparing transported horses with a non-transported control group found clear physiological changes immediately after unloading: raised heart and respiratory rates, raised rectal temperature, prolonged capillary refill time and an increased number of neutrophils – all signs of an acute stress response. A week later most values had normalised, but total serum protein and serum globulins were still elevated, suggesting that some immunological effects last longer than the most obvious stress markers.
The same research group concluded that long transport produced an acute-phase response that impaired cell-mediated immune function – which may explain why horses are often more susceptible to infection after long journeys (a phenomenon sometimes called 'shipping fever').
Interestingly, research shows that the body's adaptation to transport does not always follow a simple pattern in which a longer journey means more stress. A study that measured eye temperature (an indicator of stress-related cortisol release) in competition horses found that a 100 km journey produced a clear temperature rise suggesting the horses did not readily adapt to the situation within an hour, whereas values on a 300 km journey stayed stable – interpreted as the horses having had time to adapt physiologically during the longer trip.
In international horse sport and breeding, transport often happens by air. A study that followed more than a hundred horses through commercial air transport found that the flight affected both behaviour and health status in the horses monitored, with stress-related behaviours part of the outcome. The researchers specifically recommended that road transport to and from the airport should be minimised as far as possible, to reduce the combined load on the horse's health and welfare.
It is not only long-distance transport that matters for welfare work. Research on older horses has shown that even short-term transport produces stress-related changes in immune function, which is particularly important to keep in mind for horses that already have a more fragile health status.
In the part of the transport chain that concerns slaughter, the research points to several interacting risk factors. A review concluded that the animals' own characteristics such as age, sex, breed and temperament, the infrastructure at both the collection point and the abattoir, the design of the vehicle, environmental conditions and the quality of the human–animal interaction all affect welfare considerably before slaughter. The same review noted that current recommendations for minimum floor space in transport vehicles are inadequate and that clear guidelines for optimal waiting time at abattoirs are missing, which points to a continuing need for better regulation.
Rules and permits for horse transport in Sweden – who may drive what, and which authorities require what – are in our practical guide under Guides.
At Hästannons we believe welfare and responsible ownership belong together – whether you buy, sell, breed or ride. Read on in the series, and in our practical guides.
Yes – research shows clear physiological stress markers, especially immediately after unloading, and a raised risk of infection after long journeys.
Yes – even short transport can affect immune function, which matters for horses whose health is already compromised.
Plan rest stops, adapt to the horse's age and health, cut unnecessary mileage and keep an eye on the horse afterwards.