In a study conducted by J. B. Tasker in 1967 he had several horses go for eight days without water or feed. Most of the horses in the study were severely dehydrated by day five. If the horses had been offered grain or hay they would have dehydrated at a much faster rate. Plus the ambient temperature played a big part of the rate of dehydration. The higher the humidity and temperature - the faster the dehydration.
Most equine nutritionists use the three day mark of no water as a harbinger of death - mostly due to impaction colic and failure of organs. The age and health of the horse and the ambient temperature plays a big part.
The bottom line is - make sure horses have access to fresh clean water at all times. Impaction colic can occur quicker than three days. It is extremely cruel to not provide water to a living animal. If you can't care for one, don't get a horse.
Most equine nutritionists use the three day mark of no water as a harbinger of death - mostly due to impaction colic and failure of organs. The age and health of the horse and the ambient temperature plays a big part.
The bottom line is - make sure horses have access to fresh clean water at all times. Impaction colic can occur quicker than three days. It is extremely cruel to not provide water to a living animal. If you can't care for one, don't get a horse.