Shipping Stress Traveling means stress. There's no escaping it. Along with the fatigue that comes with bracing and balancing himself in a bouncing, vibrating trailer, your horse might find himself in an environment that is too hot or too cold for comfort, or breathing stale air in a trailer with inadequate ventilation. All of these factors can add up to one road-weary road warrior. Most short trailer trips of a couple of hours or less are not likely to have a significant impact on a seasoned traveler, but for a young or nervous animal, even a short weekend trip can be enough to prompt him to lose his appetite and make him a neurotic mess.
Dehydration is another major concern when shipping.
Both the restricted availability of water in the average trailer and the reluctance many horses have for drinking water that tastes strange can contribute. Im-paction colic is always a possibility when water intake is insufficient. On top of this, the poor ventilation in many trailers, coupled with the usual hay net hung immediately in front of your horse's muzzle, can subject him to serious respiratory stresses, especially on long hauls. The combined effect of all these stress factors might be a suppression of the horse's natural immune response, rendering him vulnerable to airborne viruses and bacteria. All of these health concerns are worth noting in any circumstance, but they're doubly important if you are traveling to a race or competition and expecting your horse to be the ultimate athlete upon his arrival.