1. Be Prepared
Know where you're going and what is required to transport your horse to that destination. This includes necessary paperwork to travel across country. Research online or call the location and find out what is required. Then speak with your vet about getting the necessary paperwork in order before you leave. Note: some requirements are time sensitive. Be sure to consider those timing sensitivities in your preparations. If you don't have your paperwork in order, it could mean extra time being stuck at border crossings for your horse in a hot trailer.
2. Directions and Maps
Have the correct directions to your destination. Look up the appropriate route on-line and buy a road map for the area to keep in your vehicle in case you need to detour while in route due to construction or weather issues. Confirm any overnight stays before you leave. Not being prepared could mean extra hours in a hot trailer for your horse.
3. Go Early
Avoid traveling during the hottest part of the day. The hottest part of the day varies depending on what part of the country/world you are in. Do your research before hand and know everything you can about your journey and your final destination. Most professional transporters get up early and are on the road during the cooler parts of the day, and allow the horses to unload and rest during the hottest parts of the day.
Open all windows and vents. If your windows do not have screens, use a fly mask to protect your horse's face or purchase an after-market screen for your trailer windows. Do NOT allow your horse to hang his/her head out of an open window with no bars. Flying debris can injure your horse, or worse, your horse could become decapitated by another passing vehicle.
Allow your horse to travel only wearing a halter. This improves skin ventilation and allows your horse to sweat naturally inside the trailer. If you tie your horse inside the trailer, enable enough slack so he can lower his head and clear his airways as he would naturally.
5. Hydration Boost
Monitor your horse's water intake and ensure he is properly hydrated before you travel. You may even want to boost up his hydration by soaking his foods and administering electrolytes before you travel. Talk with your holistic vet about the right recipe for your horse before you travel. If you plan to feed hay in the trailer, consider soaking the hay to reduce dust and particles inhaled by your horse and to boost hydration. Alternatives to hay are soaked timothy pellets or hay cubes. Add in some brewed slippery elm bark to grease up the digestive tract to prevent colic (1/2 tablespoon once or twice a day).
6. Immune Boost
Just like humans, horses become stressed during travel and are exposed to a lot of different elements that could impact a weakened immune system. Ensure your horse is healthy to travel. Talk with your holistic vet about immune boosters, such as garlic, to help keep your horse in top shape before, during, and after travel.
7. Recovery Time
Allow your horse recovery time once you have arrived at your final destination. A good rule of thumb is at least three days for every 15 hours of travel. This means your horse will need recovery time at the new destination, as well as when you have arrived back home.