It seems like many horses today should have their own frequent mileage cards, given the amount of traveling they do. We take them to lessons, competitions, trail rides, and sometimes even on vacation. However, all of that trailering can take its toll on them. So how do we keep our equine companions happy and healthy during our travels?

There are a plethora of studies out there documenting the effects of long distance travel on the equine immune, respiratory, and musculoskeletal systems.

Immune System:

Trailering causes stress that has affects at the physiological level. Cortisol, a stress hormone, increases from the start of trailering through the entire trip. It then takes 11-36 hours of rest for it to return to baseline levels. Cortisol decreases immune function and affects glucose metabolism. The white blood cell counts increase in neutrophils, decrease in lymphocyte, resulting in an increase in the neutrophil: lymphocyte ratio. This suppression of the immune system can leave horses susceptible to viruses that are common in commingling populations such as influenza and rhinopneumonitis. Horses recovered from Equine Protozoal Myelitis (EPM) are more likely to have a recurrence of the disease after long distance trailering due to this immune system suppression.

Equine Respiratory Disease and Trailering:

Tying a horse’s head in a trailer has been shown to increase the chance of respiratory disease. Think of all the airborne particulates flying around the trailer at 75 mph as you are trucking down the roads. Your horse is breathing in all of these. Horses clear debris and bacteria from their trachea in two ways. One is simple gravity. Your horse puts his head down to graze and gravity pulls the debris from the trachea out through the nostrils. The other method is mucociliary transport, thousands of tiny finger-like projections transport bacteria and debris from deep within the trachea and out of the respiratory system. Both of these methods are impaired when your horse’s head is tied to chest level.

In fact, it takes just 6-8 hours for significant numbers of bacteria to accumulate in the lungs with the head tied. This, combined with impaired immune function, can result in bacterial pleuropneumonia (infection of the lungs and lung cavity), also known as Shipping Fever. Symptoms of shipping fever include: loss of appetite; fever (usually higher than 102° F); increased respiratory rate; shallow breathing (due to pain in the chest cavity); cough (which they may try to suppress due to pain); and sometimes nasal discharge. Shipping fever is a very serious condition and can be fatal, or can lead to severe or fatal complications such as colic and laminitis.

Musculoskeletal Systems and Trailering:

While we sit in the comfort of our truck towing our horses, what is their comfort level? Being on a trailer is, in actuality, the equivalent of walking for a horse. They are constantly shifting their weight and moving their feet to stay balanced. Just keep in mind that an eight hour trailer ride for your horse is like going for an eight hour walk. Blood tests done after trailering show increased muscle enzymes similar to those in exercising horses. If you are trailering a very long distance it is wise to take one hour breaks every six to eight hours to allow your horse to rest. If this is not possible, then allow adequate rest, usually twenty-four hours, upon arrival.

Dehydration and Weight Loss:

Studies have shown that horses do not eat or drink as well when traveling, sometimes becoming up to 4% dehydrated. That degree of dehydration takes a while to be corrected through voluntary water consumption. Horses that do not eat well can lose weight and certainly not be at the top of their performance. Resist the urge to overdo the electrolytes during travel. Too much can exacerbate the dehydration if your horse is not consuming enough water (think about eating a bag of potato chips without a drink!). And while we want our horses to have something to eat and to occupy their time while we are driving, think twice too, about the hay you put in front of them. There are billions of dust, mold, and bacteria in that hay, not to mention larger particles that can be inhaled or get into their eyes. The best way to feed and water your horse on long journeys is to stop briefly every four hours. Allow your horse to be untied so he can lower his head, then feed and water your horse from the ground. This allows him to clear his trachea and to eat in a more normal position.

How to Travel Safely:

We need to be able to travel with our horses, but we also need to do it in a manner that keeps them as comfortable and healthy as possible.

Before you go:

  • Take your horse's vital signs before you get going so you will know what is normal for him. Don’t exercise excessively the day before travel. We know that maximal exercise can decrease immune function, so it is best not to start out already suppressed and tired, to boot. Give your horse plenty of hay the night before and decrease his grain meal if he gets one. Encourage him to drink plenty of water. Use water flavoring, like some of the horse teas, Gatorade or anything that gets your horse to drink. Make sure that your trailer has good ventilation. This doesn’t mean letting your horse stick his head out of the window like a dog (which I have seen!), but having proper venting and window screens to let in the fresh air and to keep out any road debris. If you don’t have window screens consider having your horse wear a fly mask when traveling to help protect his eyes. If you are driving in hot weather, try to drive at night when the temperatures won’t be so high. Also, two mats on the floor will keep your horse from being so near to the heat from the floor. A safety thermometer in the trailer will let you see what temperature your horse is contending with in the trailer. High temperatures won’t necessarily make you scrap your plans to travel, but it will let you know whether or not you should take more water breaks. And, finally, make sure your truck and trailer are in good running order before you ever hit the road!

When you arrive:

  • Once you reach your destination, make sure your horse gets plenty of rest, fresh water, and hay. He can have his normal grain meal as well. Check his temperature twice a day for the first three days at your destination to make sure that he hasn’t developed shipping fever. Try to arrive at least twenty-four hours before your competition in order to allow him to recover fully from the stress of the trip. If you have any concerns about your horse’s health when you arrive, contact a veterinarian.

Registered 2011 by Equestrian Collections
Author: Sallie S. Hyman, VMD, DACVIM, CVA

Information in this article is for educational purposes only and is not a substitute for evaluation by an equine professional. In particular, all horse owners should seek advice and treatment from a licensed veterinarian, such as TEVA, for their horses' medical care.

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