Transportation Trio: Runny Nose and Cough

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?

via e-mail

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

You might be able to keep using the hay net if you take extra care to reduce any debris and dust. First, select a grass hay that is very clean and long-stemmed with few bits to break off and become airborne. You can experiment with different hays to determine what types are more or less problematic for your horse. Also, pressure hosing the hay and soaking the hay net in a tub of clean water for a couple of hours before using it will wash off some of the loose bits and reduce the likelihood of airborne debris that can be inhaled. Hang it up to drip out most of the water before hanging it in the trailer, so you don't drip water all over the unbedded flooring and make it slick.

About the Author

Sue McDonnell, PhD, Certified AAB

Sue M. McDonnell, PhD, is a certified applied animal behaviorist and the founding head of the equine behavior program at the University of Pennsylvania's School of Veterinary Medicine. She is also the author of numerous books and articles about horse behavior and management.

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