Horse Trailering

Table of Contents

  1. Introduction
  2. Factors Affecting Horses During Transport
  3. Travel Tips to Minimize the Stress Associated with Transporting Horses
  4. Trailer Safety Kit
  5. References
  6. Related Link


The history of moving horses from one place to another dates back as far as 3500 years. Some of the reasons for transporting include: shipping horses long distances to participate in military conflicts in far- off colonies, breeding, racing competitions and slaughter. (1,2) It is documented that Queen Anne (1702-1714) had one of her race horses carried to the track in a large, horse-drawn conveyance that carried the horse in a sling. (3) The modes of transport evolved from shipping cavalry horses by sea, to moving race horses in trailers drawn by other horses, to railways until the 1920s. (1,2) By the middle of the 1900s, motorized vehicles, both vans and trailers, were the main method of moving these animals to shows and competitions. During the 1950s and 1960s, an increased use of horse trailering led to a dramatic increase in the number of horse trailer-related incidents on highways. Horses are also transported by air, but this mode of transport is reserved for the elite athletes and horses of great value, as the cost is very high.

Factors Affecting Horses During Transport

Research has proved that horses experience significant stress associated with transport. Dr. Carolyn Stull, a researcher with University of California, has defined stress as "…adverse effects in the environment or management system which force changes in an animal's physiology or behaviour to avoid physiological malfunctioning, thus assisting the animal in coping with its environment." Dr. Stull measured horses' responses to challenges in their immediate environment by measuring physiological, biochemical, immunological, anatomical and behavioural parameters. According to Dr. Stull, "…. identifying and minimizing stressful situations allows for greater well being, health and reproductive efficiency of the horse as well as protecting its performance and economic potential."

Cold or heat stress will affect the health of younger animals more than mature, healthy horses. The thermal comfort range for horses is estimated to be between -1°C and 24°C (30-75°F). Horses can comfortably adjust to temperatures in this zone by altering hair coat, sweating, homeothermy, constricting or dilating blood vessels, or changing postures or behaviour. When temperatures fall below this range, the Lower Critical Temperature (LCT), the horse must divert food energy formerly used for performance or growth to producing metabolic heat. Add in factors such as wind and precipitation and this animal needs as much as an 80% increase in caloric requirement. This must be kept in mind when transporting horses in cold weather. Thin horses or younger stock, or horses that have been clipped, will need additional high quality feed and blankets when transported.(2)

Extremely warm temperatures of 24-32°C (75-90°F) are equally threatening, as horses cannot dissipate body heat quickly enough to maintain homeothermy. The Upper Critical Temperature (UCT) is dependent on humidity, which causes respiration and sweating mechanisms to be less effective. Feed intake will decrease and water intake must be assured to combat dehydration. Avoid travel in the warmest parts of the day and keep the trailer moving to help alleviate heat stress. (2)

The type of trailer or van in which the horse finds itself, and the flooring on which it must stand, will have an impact on the horse's stress level. Slippery floors, combined with poor driving practices, will cause a horse to 'scramble' to maintain its balance. This is extremely stressful for the animal. The addition of rubber matting, sand, or wood shavings, will help to remedy the slippery floor problem and reduce the amount of vibration transmitted through the floorboards.

Research on the effects of transporting horses facing the front or back of the vehicle concluded that heart rates were lower on those animals facing the rear of the truck or trailer. The researchers concluded that horses were less physically stressed travelling backwards, as they tended to rest their rumps, dropping a hip, leaning over the forequarters, lowering the head and relaxing to the point of dozing off. (3) They were also better able to balance and brace themselves during transport and vocalized less than their front-facing travel mates. (4) Several other investigators, including Wentworth Tellington, and David Holmes, confirmed that horses facing backwards and untethered showed less signs of stress. (1)

Isolation from stable-mates, or combining horses with others that may be aggressive, will contribute to transportation stress. The Code of Practice for the Transportation of Livestock - Horses recommends segregating stallions from all other horses when they are shipped communally. Horses with shoes on the hind feet should be separated from those that are unshod. Younger and older, infirm horses should also be transported apart from other horses. (5)

Long term stress (24-48 hr.) can influence a number of systems in the horse, including immune, digestive, and reproductive systems. It can influence hormones essential in reproduction, growth, energy, metabolism and response to disease or infection. These effects can continue for hours, or even days, after the stimulus from the stressor has been diminished or eliminated. (2)

It is not advised to administer penicillin or phenylbutazone as a prophylactic measure to combat the effects of transportation-related stress. Raidal, et al., published a paper entitled "Antibiotic prophylaxis of lower respiratory tract contamination in horses confined with head elevation for 24 or 48 hours" in a 1997 issue of the Australian Veterinary Journal. The study demonstrated that the "prophylactic administration of penicillin before or during confinement did not reliably reduce bacterial numbers or prevent the accumulation of purulent (inflammatory) lower respiratory secretions in horses confined with their heads elevated." (6)

Indiscriminate administration of antibiotics may contribute to antibiotic resistance. Phenylbutazone is not indicated unless there is an underlying medical condition and will mask a fever when used inappropriately. (1)

In Ontario, the majority of pleasure or race horses are transported short distances by horse vans or trailers, ranging from two-horse tag-a-longs to sophisticated tractor-trailer units capable of comfortably accommodating up to twenty horses. Brood mares are commonly shipped for breeding to Kentucky from Canada by commercial carriers.

It is paramount that the tow vehicle and trailer or van used to move horses are in the best repair possible. All documentation should be current and valid. Failure to pass a roadside inspection will require other arrangements to deliver the horses to their destination.

Travel Tips to Minimize the Stress Associated with Transporting Horses

  • Train/teach your horse to load calmly well in advance of the event. A calm horse will likely be more comfortable on the journey. Even if you never plan to travel with your horse, it is advisable to teach it to load. Practise this several times a year; it may come in handy if an emergency trip to the veterinarian is in order.
  • Keep the trailer in good repair and in a clean condition. A trailer that travels quietly and smoothly will provide a more comfortable and less stressful ride for the horses.
  • Ensure the tow vehicle is well maintained to avoid breakdowns. It is essential that the exhaust system is in good repair and fumes are expelled to the side of the vehicle. Fumes emitted straight back under the trailer may lead to carbon monoxide poisoning.
  • Ensure the trailer has good ventilation. Avoid draughts.
  • For longer trips, plan to arrive several days earlier to permit horses' immune systems to stabilize before any major athletic endeavour.
  • 'Long-tie' horses by the cheek ring of the halter. This allows maximum head movement and facilitates sinus clearing and airway drainage.
  • Transport horses with others they get along with whenever possible.
  • Drive 'passenger-friendly'. Practice slow take-aways. Careful braking and smooth cornering are key elements to towing a trailer in a responsible manner. Always 'think ahead'.
  • Plan ahead. Chart a route and time of day when traffic is minimal and the weather is conducive to horse comfort.
  • Offer hay and water, but no grain. Water horses prior to departure and every four hours for longer trips to help combat the threat of dehydration. Hay serves as a pacifier and helps retain water in the gut during transit. Refrain from feeding grain, as stress affects gut function, causing grain to sit and ferment with the possible result of colic.

If international borders are to be crossed as part of the journey, ensure all documentation for all horses is on board and current. A negative Coggins test is mandatory for all horses travelling into the USA. 'Temporary entry' (from Canada into the USA and returning within 60 days of date of entry) requires horses to be negative for equine infectious anaemia (Coggin's test) within 180 days prior to entry into the USA. (7)

Trailer Safety Kit

Keep the following items in an emergency kit in the trailer or tow vehicle:

  • Complete equine emergency kit
  • Extra halters and lead shanks
  • Sharp knife
  • Wire cutters
  • 100 ft of 1/2" rope
  • small tool kit or 'leatherman' tool, including wire cutter, knife, tweezers, etc.
  • jumper cables
  • two flashlights with extra batteries
  • roll duct tape
  • flares
  • cell phone
  • phone number directory with numbers for your veterinarian and border crossing veterinarian
  • trailer jack
  • spare tire (complete with air)
  • spare wheel bearing
  • cash

Trailering horses can be a stressful endeavour for both horses and drivers, but practising a few preventative measures can make the trip safer and more enjoyable.


  1. Ball MA. Transporting horses. The Horse Interactive 1998; April.
  2. Stull CL. Physiology, balance and management of horses during transportation. Proc Horse Breeders and Owners Conference 1997
  3. Cregier SE. Land transportation of the horse. Live Animal Trade and Transport Magazine 1989; November: 43-44.
  4. Warran NK, Robertson V, Cuddleford D, Martin DJ. Effects of transporting horses facing either forwards or backwards on their behavior and heart rate. The Veterinary Record 1996; (6, July): 7-11.
  5. Recommended Code of Practice for the Care and Handling of Farm Animals - Transportation. Canadian Agri-Food Research Council, 2001.
  6. Raidal SL, Taplin RH, Bailey GD, Love DN. Antibiotic prophylaxis of lower respiratory tract contamination in horses confined with head elevation for 24 or 48 hours. Australian Veterinary Journal 1997 Feb; 75 (2):126-131.
  7. Export Inspection and Certification: Accredited Veterinarians' Manual, Section 4. Canadian Food Inspection Agency, August 2000: p. 14.

Recommended Code of Practice for the Care and Handling of Farm Animals - Transportation (Canadian Agri-Food Research Council)

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