Improving Travel Conditions

While there have been many changes in the equine world in the past several decades, no change has been more dramatic than that experienced by horse transportation. The change, literally, has been from hooves and rails to wheels and wings. While this has made the horse world smaller, it also has brought new stresses and problems associated with the logistics of these equine excursions.

In the early 1900s, equine transportation was either by hoof or railroad car. Circuses traveled by train, and when they arrived at a destination, teams of draft horses conveyed the big top and assorted equipment and animals to the show's location. Racehorses often traveled by rail from track to track. In the West, groups of horses were moved on the hoof in trail drives. In the Midwest, it was not unusual for a stallion owner to travel from farm to farm with a stallion walking or jogging along behind a buggy to service mares.

The switch from utility to recreation as the main purpose of horses, plus exploding machine-age technology, changed all that. Horses not only crisscross our land in vehicles by the thousands, they also travel from country to country for international competitions and races. Air travel has removed all international travel barriers.

As is the case with all aspects of the equine industry, progress has been at something of a price, as advanced transportation has produced its own unique problems.

Some of the problems are psychological in nature. The horse is a prey animal whose prime defense is flight (which requires considerable space), and transportation means confinement in a restricted space. Other problems affect the respiratory system, with the horse's breathing apparatus being assaulted by dust particles and other pollutants in poorly ventilated vans and trailers. Still other problems have resulted from assaults on the horse's rather delicate digestive system (see "Ulcers from Shows and Training" on page 14). The list goes on.

While man has created these problems, he has also sought to solve them with ongoing research aimed at unraveling the mysteries of the stress created by equine travel. Equipment has been improved as knowledge and understanding have expanded. Guidelines for appropriate treatment of horses being transported have been established.

Ironically, much of the progress in recent years has been stimulated by an aspect of the equine industry that is viewed by many as negative--equine slaughter. When Congress passed the Farm Bill in 1996, it gave the Secretary of Agriculture authority to regulate the commercial transportation of equines to slaughter by persons regularly engaged in that activity within the United States.

Because there are only a few slaughter houses in the United States and Canada, horses sent to them tend to be transported for long distances when compared to other animals headed for slaughter, such as cattle, sheep, and pigs. There was a growing concern within the equine community that many of these horses were treated inhumanely while being hauled cross-country to slaughter plants.

In the wake of the Congressional mandate, research was conducted at institutions such as Colorado State University, University of California, Davis, and Texas A&M University to find out what abuses truly did exist and what should be done to correct them.

The ultimate result of that federally funded research was establishment of guidelines for horses being transported for slaughter with official, nationwide implementation on Feb. 2, 2002. While the guidelines were designed for horses on their way to slaughter, there is much in them that can be applied to the transportation of horses in general. More about that in a moment.

Transportation Conferences

The dissemination of information on equine transportation has been helped by two international conferences--one in 1999 and another in 2003--where research information was shared. The 1999 session was held in the United States, and the 2003 conference was held in England. While only a small number of individuals attended the first conference, there were representatives from 23 countries at the 2003 gathering. They included veterinarians, researchers, shipping agents, insurers, regulators, engineers, flying grooms, and competition team managers.

Catherine Kohn, VMD, PhD, Dipl. ACVIM, professor in the Department of Veterinary Clinical Sciences at The Ohio State University and a veterinarian involved with the United States Eventing Team, told attendees at the 2003 conference that shipping fever (respiratory ailments) is a problem with up to 12% of the horses traveling long distances via road transportation, and that malady often afflicts up to 30-40% of horses involved in air transportation.

She made these points, according to the report:

  • The environment of the traveling horse might be significantly contaminated with particulate and molecular pollutants, including allergens, irritants, and infectious agents.
  • Ventilation is often poor, particularly in stationary vehicles and airplanes, and this is often compounded by high stocking densities.
  • Poor ventilation is often associated with inappropriately high temperature and relative humidity.
  • Thermoregulatory responses to high temperature and relative humidity involve increasing respiratory rate and depth, which tends to increase inhalation of potential pathogens, while sweating causes dehydration.
  • Head posture has been shown to have a major influence on the health of the lower airways and is probably an important factor in the development of shipping fever.
  • Other problems associated with transport include weight loss and gastrointestinal disease. (Reduced water intake can affect gut function and result in colic or diarrhea. The stress of travel also can be a root cause of gastric ulcers.)

Kohn also discussed the importance of pre-travel monitoring and preparation, good transport methods, adequate time to recover upon arrival, and prompt therapy of sick animals.

Still other topics discussed at the session involved vehicle design, jet lag, and how transportation affects performance. Another focus involved the transmission of disease by horses that are transported from one country to another.

Peter Timoney, FRCVS, PhD, head of the Gluck Equine Research Center at the University of Kentucky, told the group there has been a massive increase in the international movement of horses during the past two decades and that, with the transport of horses and semen being at an all-time high, the single most important factor affecting dissemination of equine infectious diseases is international trade.

Another U.S. participant at the 2003 conference was Carolyn Stull, PhD, of the University of California, Davis, who was involved in research that led to the U.S. transportation to slaughter guidelines and who is continuing that research.

Stull and Anne Rodiek, PhD, a professor of animal science at California State University in Fresno, conducted a study using 15 mature, healthy horses that were experienced travelers. Their physiological responses were documented during 24 hours of road transport, followed by a 24-hour recovery period during which the horses rested in individual stalls.

It was found that the horses involved in the study lost about 6% of their body weight during the 24 hours of travel. However, it also was found that they regained most of the lost weight during the 24-hour recovery period. The loss of weight was attributed to heat dissipation, sweat loss, and decreased gut fill during travel.

In addition to body weight of horses involved in the study, white blood cell counts also were measured as a general indicator of health. Transportation stress can also be measured, in part, by the concentration of the hormone cortisol. The concentration of cortisol in blood circulation began to rise when the horses were loaded and continued to rise during the 24 hours of transportation, peaking at the end of the trip.

A report on the study stated that: "After unloading, the stress of transportation ceased and cortisol concentration dramatically decreased. This large increase of cortisol during transport influences the immune system, and its influence can be measured by the ratio of two types of white blood cells, namely the neutrophil:lymphocyte (N:L) ratio. The ratio also increased during transit and did not return to baseline within the 24-hour recovery period. This continued elevation in the N:L ratio may contribute to disease susceptibility following long-term transport. Horses in this study that underwent 24 hours of transport in hot, summer conditions clearly showed physical responses that included changes in stress measures (such as) serum metabolites and dehydration, and immune indicators (such as) body weight and rectal temperature."

In the wake of their findings, the researchers offered these Recommendations for Minimizing the Stress of Transport:

  • Start with a healthy horse. Horses with sub-clinical or clinical respiratory disease should avoid transport except in emergency situations. Consult a veterinarian with these cases prior to shipping. 
  •  During long-term transport (greater than six to eight hours), do not elevate or restrict movement of the head and neck by cross-tying. A small box stall that allows the horse to drop its head is preferred for minimizing stress and susceptibility to disease after transport.
  • Dietary adjustments are not necessary in horses shipped short distances. Horses intended to endure long transportation trips should be provided with feed and water on a regular schedule. Laxatives, such as bran mashes, might not be necessary. Some nervous horses might develop loose manure or diarrhea and could become dehydrated from the loss of fluids.
  • If you provide hay to your horse during transport, make sure it is good-quality hay with minimal dust and mold.
  • Water should be offered every six to eight hours if possible. However, many horses will not drink water during transit.
  • Relative humidity and environmental temperature rise quickly in stationary closed vehicles. Horses should be unloaded upon arrival or during stops to minimize thermal stress, especially during summer.
  • Horses with respiratory ailments, such as shipping fever and pneumonia, might not show clinical signs for two or three days following transport. However, depression, lack of appetite, and the development of coughing and nasal discharge might be signs of shipping fever. Death within 30 days following transport due to pneumonia has been reported in horses transported over durations of eight to 48 hours. Daily recording of rectal temperature is advisable for a month after shipping. A veterinarian should be consulted for horses exhibiting any of these signs.

The researchers also concluded that the way in which a horse was confined had a definite bearing on his overall health. The poorest approach, they concluded, was to cross-tie a horse, and the most beneficial approach was to allow the horse to be free within a small, box stall-like area.

Additionally, the researchers reported that elevation of the horse's head restricts the range of neck movement, compromises the immune system, and increases the number of bacteria in transtracheal aspirates (fluid from the horse's airway). The increase in bacteria is thought to be the result of a decrease in clearance rate of bacteria from the tracheobronchial secretions in horses that are confined and unable to lower their heads. Thus, they reason, tying horses head-high for long trips might predispose them to respiratory disorders.

Can Supplements Help?

A possibility that has long tantalized researchers and horse owners is that some form of supplement might help prepare a horse's body for the rigors and stress of transportation. Stull and her colleagues at Davis conducted one such study and reported on it in the Equine Veterinary Journal last year.

A commercially available adaptogenic herb supplement was tested which contained extracts from four plants: Siberian ginseng, Chinese magnolia vine, golden or arctic root, and Asian devil's club. In her paper on the study, Stull said: "These herbs are considered to have 'adaptogenic properties' described by Russian scientist Lazarev in 1947 as properties that allow an organism to counteract stressors by generating non-specific resistance as well as potential antioxidant activity, anti-diabetic properties, and effects on the hypothalamic-pituitary-adrenal system."

Nineteen mature horses were involved in the study, which was conducted over a 30-day period. Ten of the 19 horses were fed the herbal extract once a day for 30 days, while the other nine horses received a placebo.

On Days 1 through 28, horses remained in stalls and consumed their assigned diet of chopped alfalfa with either herbal extract or the placebo top-dressed on the hay and combined with molasses to insure ingestion. On Day 28, six horses that had received the supplement and six that had received the placebo were loaded onto a commercial van for a trip that lasted 24 hours. Seven of the horses--three of them on the herbal supplement and four on placebo--were left behind in their stalls.

The transported horses were provided with alfalfa hay via haynets, and they were offered water four times during the trip. The total distance covered during the 24 hours was 1,021 miles. The study took place in September and October of 2000, with temperatures in the moderate range.

Once the trip was completed, the transported horses were housed in stalls for a post-transport 24-hour recovery period. Horses were weighed and blood samples were analyzed. The loss of body weight, Stull reported, was "highly significant," with the transported horses losing 4.5% of their body weight. The other parameters associated with stress, such an increase of cortisol in the bloodstream, were elevated, as was the case in the Davis study discussed earlier.

However, the study found that there were no significant differences in stress parameters for transported horses on the herbal supplement when compared to those fed the placebo, according to Stull.

The study also reinforced the earlier finding that stress levels are exacerbated when horses are cross-tied rather than allowed their freedom during transportation.

Learning from Slaughter Horses

One of the key researchers involved in establishing the federal guidelines for transporting horses to slaughter was Temple Grandin, PhD, an associate professor of animal science at Colorado State University. She also is the source of information in Guidebook for USDA's Slaughter Horse Transport Program.

In the book, Grandin discusses a wide range of subjects, from horse psychology to proper conveyances for transporting horses. For example, she states that a trailer compartment should be high enough that a horse standing with all four feet on the floor can have full range of motion of its head without touching the ceiling. "The withers or rump must never touch the ceiling," Grandin wrote. She also pointed out that non-slip flooring is essential in all areas where horses are handled--be it the trailer itself or holding pens.

As mentioned earlier, portions of the guidelines for transportation of slaughter horses are applicable to horse transportation in general. Here is an excerpt from the guidelines as authored by Grandin that helps all horse owners:

"Auction market employees, truckers, and all people handling horses should handle them quietly. Yelling and loud noise should be avoided. Horses have very sensitive hearing and can hear high-pitched sounds that humans cannot hear. Horses will often balk and refuse to move if they see shadows or objects on the floor. If a horse stops, allow it to investigate the shadow before urging it to move forward. The wide spacing between horses' eyes gives them poor depth perception while moving. A horse will often move willingly if it is allowed a few seconds to look at a shadow, reflection, or moving object that it sees up ahead.

"Horses may balk at entering a dark place from a brightly illuminated place. They sometimes refuse to leave a trailer that is in bright sunlight to enter a darker building. However, horses may move toward the same facility well at night or on a cloudy day. Artificial lighting often has little effect on bright, sunny days because the sun is much brighter than lamps. The ideal lighting for handling animals looks like a bright, cloudy day and creates no shadows. Lamps installed in a trailer will often facilitate entry into a trailer at night. The best lighting is indirect. The lamp should illuminate the inside of the trailer, but not glare directly into the eyes of the approaching horses.

"Objects that move suddenly will scare horses," she goes on. "A person standing up ahead who makes sudden jerky motions may cause a horse to startle. Sudden motion scares; slow, steady movement has little effect."

The question of how long horses should remain in transit without being unloaded is also addressed in the guidelines, as is the matter of watering them. In authoring the guidelines, Grandin quoted from studies conducted by Stull and Ted Friend, PhD, professor of animal science at Texas A&M University. Here is what Grandin had to say:

"Prior to loading, horses should have access to feed and water for at least six hours. Leaving horses on a trailer for too long without water can compromise their welfare, especially during hot weather. Stull's work showed that after 27 hours of travel, there were major health concerns. Further research by Friend and colleagues at Texas A&M University indicates that during hot weather, 24 hours is the maximum amount of time a horse should be allowed to remain on a trailer without water. This study was conducted under very hot conditions of 84° to 95°F, and at 24 hours, several horses were showing signs of severe heat stress. Further studies at Texas A&M indicated that most horses will drink from a trough in the trailer (when the trailer is stopped).

"There are practical difficulties to watering horses on a trailer," continued Grandin. "Unless these difficulties are overcome, the trailer must be stopped for at least 30 minutes to allow horses to relax. They will be more likely to accept water if they are given an opportunity to relax and urinate. Horses traveling in the hot southern regions of the United States during the summer must be watered en route even if the journey lasts less than 24 hours. Horses should be unloaded and rested on trips that last more than 24 hours. A stop should last eight hours to allow enough time to rest, feed, and water the horses.

"Rest stops are a controversial subject," she adds. "In Europe, rest stops are required every nine hours. It is possible that stopping too frequently may cause more stress, especially in horses that are not completely tame. For these horses, loading and unloading may be the most stressful part of the trip."

Take-Home Message

There are a couple of take-home messages from the studies and the conclusions drawn. One is that horses are individuals. Some seem to actually relish travel, while others are "stressed out" when transported even short distances. An important attribute of a rodeo horse that crisscrosses the country, for example, is that it must "travel well." If one is to travel extensively with a horse, it is important that the animal be a good traveler.

Another take-home message is that there are ways to minimize travel stress. Implementing the suggestions given by the Davis researchers is a good way to start.

About the Author

Les Sellnow

Les Sellnow is a free-lance writer based near Riverton, Wyo. He specializes in articles on equine research, and operates a ranch where he raises horses and livestock. He has authored several fiction and non-fiction books, including Understanding Equine Lameness and Understanding The Young Horse, published by Eclipse Press and available at or by calling 800/582-5604.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More

Free Newsletters

Sign up for the latest in:

From our partners