A sling is a supportive harness that keeps an animal in a standing position. According to animal clinic Homestead Veterinary, one of the earliest known uses of horse slings was by Spanish explorers transporting their horses to the Americas. Horses were put in slings that were attached below decks; they allowed the horses to move fluidly with the ship's movements, while taking weight off their feet. Today, horse slings are generally used to help mend leg or hoof fractures, or for cases of laminitis, an inflammation in which a horse's hoof becomes too painful for it to walk on. If you need to keep your horse in a sling, avoid prolonged suspension because pressure sores may begin to develop.
Fold a large, thick blanket into a rectangle the length of your horse's torso. Make sure that the blanket you've chosen is big enough to accommodate your horse, as well as thick enough to act as padding between its body and the sling straps.
Lay the folded blanket on the ground. Lay two 6-foot nylon cargo straps, each with an attached strap hook at one end, underneath the blanket and perpendicular to the direction in which the blanket is lying. Make sure the straps are spaced about as far apart as your horse's armpits and hip flexors. These straps will act as the sling that will support your horse's weight, so keeping them accurately spaced is important.
Slide the blanket, with the straps still beneath it, under your horse's torso. Have a friend or family member stand on the opposite side of the horse and help you centre the blanket beneath it. Once the blanket's centred, take a strap in each hand and instruct your helper to do the same. Carefully lift the straps, bringing the blanket up in direct contact with your horse's chest and belly. If you need to, adjust the spacing of the straps so one is nestled in your horse's armpit area, and the other is nestled in the hip flexor area.
Place the open ends of the two straps up and over your horse's torso, and instruct your helper to continue holding the blanket up against the chest and belly of your horse so that it doesn't fall during this step. Each strap should now be overlapping its ends on your horse's back.
Beginning at the strap closest to your horse's neck, loop one end of the strap through the metal strap hook attached to the opposite end. Pull through the hook until you have about 2 feet of space between the strap hook and your horse's back. Use a pencil to mark just below where the hook is on the strap end threaded through it.
Disconnect the strap from itself by unthreading the strap out of the metal hook. Find where you made your mark and tie an overhand knot at that point. Slide the strap back through the attached metal hook. The knot you tied should now stop the strap from going farther through the hook and will stop the strap from completely tightening around your horse's torso when your horse is lifted.
Repeat the last two steps with the nylon strap closest to your horse's tail.
Move your horse below the prongs of your forklift, making sure your helper keeps the blanket snugly against the horse's underbelly. Make sure you have bought, borrowed or rented a forklift capable of lifting at least one thousand pounds.
Stand on a ladder for height, and pull the two nylon strap ends up and over the outside of the two forklift prongs, so that one prong is braced against the front strap, and the other prong is braced against the second strap. Tie the two strap ends in a flat knot.
Raise the forklift's prongs. The prongs should lift the now knotted single strap that is looped over them. This movement should pull the straps taut above the horse, bring the blanket snugly against your horse's chest and belly, and lift the horse off its feet.
Slinging a horse can be dangerous for you and your helper. Be very careful following each of these steps, and observe your horse's temperament throughout the process to make sure it doesn't try to buck or bite you. Sedation may be necessary.