Q: Every time we trailer our horse, he arrives with a cough and runny nose. Our vet has suggested that he is sensitive to the dust from bedding in the trailer or bits of hay from the hay net bouncing around in front of his nose. It has been suggested that we should stop using a hay net and bedding in the trailer for him. But he travels much better with hay in front of him. Without something to keep him busy, he tends to start stomping and moving about more than we like. Any suggestions on how to keep him calm without hay, or keep the dust down in the trailer?

A: Those are good questions that we hear a lot more since the work of researchers at UC Davis and elsewhere investigating various transport stressors has shown so clearly how dusty a trailer can be with bedding and hay. They have shown how the ventilation in most trailers typically circulates debris right into horses’ faces. Sometimes people just try to tightly close up the trailer, which is definitely not a good idea.

Ventilation is a must because of the risk of exposure of the animal compartment to exhaust fumes. Even if no exhaust is leaking into the trailer, the air in a tightly closed trailer becomes pretty nasty with ammonia and other gases from urine and feces. If you look at the current information, you wonder why more horses don’t show signs of respiratory problems with transport.

For more information on transportation stress from Dr. Carolyn Stull at UC Davis, including respiratory challenges in horses, see https://www.vetmed.ucdavis.edu/vetext/local_resources/pdfs/pdfs_animal_welfare/physioBalanceMgtHorsesTrans97.0308.pdf