The University of California Davis has developed a sling for lifting large animals.
From their website:
The UC Davis LAL (Large Animal Lift) is a device used for lifting down horses by the skeletal system using lightweight equipment that can be applied easily to a down horse.
Background: The development of the ‘Anderson Sling’ at UC Davis was a joint effort of Dr. John Madigan, Richard Morgan and Charles Anderson. When Madigan returned to UC Davis from private practice in 1983 he began seeing a large number of neurological patients. Madigan, along with Anderson a welder and inventor, and Richard Morgan, a large animal clinic supervisor, teamed up to develop and test what would become the sling used around the world to help weak horses and assist with anesthesia recovery. Following completion of the sling Madigan found many circumstances in the field and in clinics where there was a need for a simplified device that was easier to put on a down horse. Madigan again enlisted the help of Richard Morgan, Charlie Anderson, and Greg Ferraro from the Center for Equine Health, to develop a useful device for assisting horses to stand which could be put on a down horse. The Anderson sling works well for longer term lifting, but is difficult to put on a down horse without sedating or anesthetizing the animal and this then further limits the ability to assess the horse once lifted.
The UC Davis Large Animal Lift is a lightweight, simple to use, affordable piece of equipment which include the following:
Lifting down horses in the field using a tractor, back hoe or other overhead device.
Anesthesia recovery assist
Pulling recumbent horses from stalls or trailers
Lifting or pulling horses stuck in mud, ravines etc.
Lifting weak older horse that get down and can’t rise
Preventing horses with pelvic injuries or other orthopedic injuries from laying down.
The LAL can be used to pull a horse to a skid device and then lifted out of many difficult
circumstances.
You can get more information at their website by clicking HERE.