Pinch Test

Dehydration, or the loss of body fluids, is a dangerous condition that can easily go undetected in horses. It is not easily recognized until the animal has lost 5% or more of its body weight. A loss or 12 to 15% of body weight in water is life threatening.

"The pinch test is a handy way to test a horse's hydration level by assessing the skin's turgor, or normal state of distention and resiliency," states Storey's Barn Guide to to Horse Health Care + First Aid. In the shoulder or neck area, pick up a fold of the horse's skin between your thumb and forefinger. Pull it away from the body. Then release the skin and observe how long it takes to return to its normal flat position. In a healthy, well-hydrated horse, the skin will return to this position almost immediately. In colder weather, it may take slightly longer, but not more than 2 seconds.

If after 3 seconds the skin remains markedly peaked, the horse had suffered some fluid loss. If after 5 to 10 seconds the skin appears "tented," the horse is suffering from moderate to severe dehydration and should be seen by a vet.