Most of us are familiar with the simple skin-pinch test to check a horse for dehydration: Pinch an area of skin and pull it away from the horse, then release the skin and count how long it takes for it to flatten again. Anything more than three seconds can indicate dehydration.
Less well known, however, are factors other than hydration that can affect the test results. For example, skin elasticity varies depending on the location on the body. The neck is a common site of a skin test, but the point of the shoulder may offer more accurate results because the skin there has a bit more “give” to it, making it easier to pinch and pull. In addition, age can affect skin elasticity. The skin of a horse over the age of 15 isn’t going to snap back as quickly as a yearling’s, even if the older horse is sufficiently hydrated.
Also remember to interpret the pinch test in context. If your horse isn’t looking colicky, ill or otherwise distressed by the heat, chances are he’s not significantly dehydrated even if his skin seems a bit less elastic than normal. Just make sure he has clean, fresh water---perhaps tempt him to drink by mixing in a bit of apple juice---and keep a close eye on him. Call the veterinarian if you see anything else that makes you worry.
This article first appeared in EQUUS issue #453, June 2015.