Definition: any journey in a truck, trailer, boat, or airplane of greater than 5 hours is considered "long distance."
Horses lose 2-5 pounds of body weight for every hour they travel, and that's in cool weather. This can increase dramatically in hot weather due to evaporation at the body surface or frank sweating.
Effects of long distance travel on the body include:
Suppression of the body's immune system.
Impaired clearance of dust, bacteria, and any foreign substance from the respiratory system.
Decreased water intake resulting in dehydration.
Major complications associated with long distance transport include:
Pleuropneumonia, otherwise known as 'shipping fever'. Pleuropneumonia is a bacterial infection of both the lungs and the pleural space that surrounds the lungs (See PetPlace.com articles on Pleuropneumonia and Bacterial Pneumonia).
Dehydration. Because horses often refuse to drink while traveling, they may lose enough body weight to become clinically dehydrated (loss of at least 5% of body weight).
Colic, primarily secondary to dehydration. When horses lose body water, the highly fibrous food (hay) that is in their digestive tracts also becomes dehydrated. This is a very big risk factor for impaction colic.
Complications of long distance travel can be minimized with careful planning. This includes:
Plan for frequent stops. Horses should be offered water and food every 2-4 hours, depending on the weather. In hot humid weather, they should be offered water at least every 2 hours.
Plan for frequent stopovers. Horses should not be asked to travel more than 8 hours at a stretch unless absolutely unavoidable (for instance, a flight to Australia….).
If you have any concerns, have your veterinarian give your horse a thorough physical examination during the week prior to travel. Chronic diseases often worsen during travel.
Delay your trip if your horse has had an infectious respiratory disease, such as influenza, during the 4 weeks preceding your trip. Prior respiratory disease will predispose your horse to developing pleuropneumonia.
Avoid impaction colic by having your veterinarian give a gallon of mineral oil plus water and electrolytes via nasogastric tube 4-12 hours before long distance transport. Alternatively, get some mineral oil into the horse in a bran mash. DON'T syringe feed your horse with mineral oil - this may lead to aspiration pneumonia.
Accustom your horse to eating soaked hay during the two weeks prior to the trip. Eating soaked hay for one day prior to travel and during travel will provide your horse with much needed water. This will help avoid both dehydration and colic.
Accustom your horse to drinking flavored water (most horses enjoy water flavored with apple juice) so that he will not reject 'foreign' water, or bring an adequate supply from home.
Signs of depression or not eating.
Signs of respiratory disease such as increased respiratory rate or effort, coughing, or discharge (especially any thick or discolored discharge) from the nostrils.
Fever, which may indicate either overheating or infection. Any temperature greater than 101.5°F is considered a fever, and warrants a call to your veterinarian. A fever greater than 104°F is indicative of either overheating or severe infection. You should take the temperature of your horse after long-distance transport, once it's settled down in the stall, and daily in the morning thereafter. Any fever spikes should be brought to the immediate attention of your veterinarian.
Signs of colic or impending colic such as decreased amount of manure, dry manure, decreased appetite, or signs of abdominal pain, such as pawing, looking at the side, or rolling.
Excessive sweating, decreased water intake, or decreased urination (this may signal that your horse is dehydrated).
Increased heart rate (for most horses, a heart rate greater than 44 beats per minute is elevated).
Any of the above signs would warrant an immediate call to your veterinarian.
The wise traveler will arrange for a veterinary visit as soon as possible after arrival at your destination. Your veterinarian will be looking for signs of respiratory disease, dehydration, and colic.
Diagnostic tests will include a thorough physical examination, with careful auscultation (listening with a stethoscope) of the chest.
Depending on the distance traveled, and the physical condition of the horse, your veterinarian may choose to take blood for a complete blood count (to look for signs of infection), and a chemistry profile (to look for signs of organ dysfunction, especially kidney function, which can suffer due to dehydration).
If your horse shows any signs of respiratory disease, your veterinarian may choose to look at the airways using an endoscope, and will often choose to look at the chest using ultrasonography. Ultrasound is a very sensitive method for detecting fluid in the chest. (See Figure 4)
If your horse has shipping fever (pleuropneumonia), your veterinarian will treat with broad spectrum antibiotics. Your veterinarian may also need to drain the chest of excessive fluid build-up. Frequently, shipping fever is so severe that the horse must be sent to a referral hospital where around-the-clock care can be given.
If your horse shows signs of colic, your veterinarian may choose to perform an examination per rectum (a 'rectal'), and will probably want to pass a nasogastric tube. Depending on his findings, your veterinarian may wish to treat with intravenous fluids.
If your horse is dehydrated your veterinarian will administer fluids containing electrolytes using a nasogastric tube. If the dehydration is severe, your veterinarian will probably opt to administer intravenous fluids.
If your horse is overheated, your veterinarian will use aggressive measures to cool him down. Once the horse's temperature reaches 104°F due to overheating, he is on his way to heat stroke. Your veterinarian will facilitate a rapid cool-down by continually bathing your horse in cold water, offering cool (not ice cold) water to drink, and administering nasogastric and intravenous fluids. Your veterinarian will avoid placing cold towels on your horse - they will soon heat up and act as an insulator to trap body heat.
Try to make any feed changes two to four weeks before long-distance transport.
Soak your horse's hay in water to increase the amount of fluid he is getting.
If your horse enjoys wet feed, then a bran mash with a few 'goodies', such as apples and carrots, will also help to deliver fluid to his system.
Let your horse have a well-earned rest when he reaches his destination. It may take your horse as long as 1-2 weeks to regain the weight that he lost during travel.
This rest should not be stall rest. Rather, your horse should have as much access to turn-out as possible to help him stretch his muscles and help his gastrointestinal function to return to normal. If you do not have good access to turnout, then you should hand-walk, long-line, or bring your horse on very gentle rides a minimum of three times a day.
Again, monitor your horse's temperature once to twice daily in the week after arrival. A gradual rise in temperature may be your first clue that your horse is developing a respiratory infection.
Monitor your horse's daily manure production and urine production.