Understand NO grain or rich feed prior to travel.....no matter how much you love your horse. Stop grain at least 1/2 day before transporter arrives for loading. Hay is good but use a flake that has more grass than alfalfa, etc. Send 1-2 bales of familiar grassy hay along so your horse's diet remains familiar.
Have the health paper work ready. This includes vet papers for shots, health, coggins tests, brand inspection, etc. No reputable transporter will load a horse without current health papers.....not even for a short trip in-state.
Horse must have a basic halter and lead rope.....don't dress your horse up in it's best show tack!!
Discuss any and all issues in advance. This is for the horse's and the handler's benefit.
If the transporter allows for extra things to be shipped along with the horse....label your things and make a list to be given to the transporter and the person receiving the horse(s), even if this is the owner.
For picky drinkers, blend Mountain Dew or Kool Aid in drinking water for a week prior to travel for horses that are finicky about their drinking water. Then send enough with the horse for the trip. This is commonly used to convince a horse to drink while traveling.
Shipping boots are not a good idea unless the horse is used to wearing them. If you really think they are necessary put the boots on and leave the horse tied for several hours to test their behavior. A shipping boot may sound like a good idea but if the horse kicks at them continually then it may injur itself . They can also add excess heat and stress to the horse's legs. Many transporters have ramps for loading/unloading so there is little risk of injury. Ask the transporter if they have ramps.
Transporters don't supply blankets for sanitary reasons. Send a light blanket along if it seems necessary.
Transporting a horse incorrectly can cause shipping fever, thrush, cuts and abrasions, colic and emotional scars. The best way to prevent problems is preparation. It is important to remember that transporters are in the business to move your horse with the least amount of stress possible but they are not in the business to train your horse. Adequate groundwork on your part will help to ensure that your equine companion has a less stressful trip. Elevated electrolytes, proboscis and mineral oil can be ingredients for a successful transport. These are very easy to administer prior to shipping and help in reducing stress for touchy/inexperienced travelers.