There’s no doubt that hauling experiences can be stressful for a horse. In fact, studies show that horses undergoing transport are more likely to develop gastric ulcers as well as negative changes in gut microflora which can lead to problems like horse colic or diarrhea.
To make matters worse, horse transportation stress can also be heightened by other factors including temperature changes or vibrations in the horse trailer (1).
How Does Horse Transport Affect the Equine Microbiome?
New research suggests that even short trailer trips can negatively impact your horse’s gut microbiota, the bacterial population in the hindgut that helps with proper digestion, immune function, and nutrient and energy production.
Researchers in one study sampled horse fecal microbiota and found a discernible decrease in the presence of Clostridiales after trailering (2). This species of bacteria appears to be more plentiful in healthy horses, suggesting that negative impact to the equine microbiome may be an additional problem with horse transportation.
Additionally, withholding hay from horses during long-distance trips can lead to a higher incidence of gastric ulcer development. Another study that evaluated the effects of transport showed that horse transportation over 500 miles increased gastric squamous ulcer scores and led to severe ulceration in some horses (3).
Should I Feed My Horse Before Trailering?
To reduce your horse’s chances of developing gastric ulcers, feeding forage (but not grain) before a journey is a good idea as this will help to buffer acidity and also keep the equine GI tract moving. Because of its high calcium content, feeding alfalfa appears to have an additional buffering effect if fed one to six hours before transport (3).
Feeding hay during trailering comes with some risks, one being pneumonia, which can occur as a result of inhaling dust particles and not being able to eat in a natural head-down position. Horses also appear to have an increased risk of choke (esophageal obstruction) while eating hay during transport.
How Do You Relieve Stress in Horses?
Eliminating horse transportation altogether is obviously not reasonable or practical, but there are proactive steps you can take to reduce stressful situations associated with hauling.
First, make sure your horse is familiarized with loading and unloading before expecting him to take a long ride in it and likewise, only use shipping boots or wraps if the horse is accustomed to them.
Second, ensure the trailer has adequate ventilation to avoid added heat stress, and plan to stop and offer water every 4-6 hours (every 3-4 hours in hot weather). Also offer hay during these stops, if possible.
If stopping isn’t possible during long transport, horses will need access to hay, but it should be as dust-free as possible; therefore it’s recommended to thoroughly soak hay in water before placing it in a hay net in the trailer. Additionally, give horses as much head movement as possible in the trailer.
Finally, to address changes in the gut microbiome which can occur as a result of horse transport stress, consider feeding an equine probiotic paste both several days before long transport, as well as a day or two afterward to help restore beneficial bacteria in the gut. Using these high-powered probiotics for horses can make the entire horse transportation experience the best it can be for both you and your horse.