Instructions
Check the horse's capillary refill time for signs of dehydration. Simply lift the upper lip away from the gum, then press on the gum with your thumb, forcing the blood away from the area to which pressure is applied. The gum will turn white. If it takes longer than two seconds for blood to return to the area (it will turn pink again), the horse is probably dehydrated.
Perform a skin elasticity exam. Pinch about two inches of skin on the horse's neck between your thumb and forefinger, then let go. If it takes longer than two seconds for the skin to return to its normal position, dehydration is likely. Performing this test on other areas of the horse's body might not yield accurate results.
Monitor the amount of water your horse drinks in a day. This is impossible with automatic waterers, which simply refill when emptied, so provide the horse with at least two buckets of cool, clean water. If the level of water doesn't decrease significantly in six to eight hours of stall time, the horse is probably in danger of dehydration.
Check the inside of the horse's mouth for lack of moisture. The tongue should be moist. Tackiness or dryness around the gums and teeth is a sign of dehydration.
Examine the horse's eyes. If the eyeballs appear sunken or set more deeply than usual into the skull, dehydration might be an issue. Additionally, dehydrated horses often have eyes that are described as "lusterless," with a lack of pigmentation and clarity.
How to Identify Dehydration in a Horse
Dehydration is a particularly dangerous condition for a horse. It usually occurs during the summer when horses are ridden too hard without an adequate water supply. Some horses sweat more than others, and therefore lose a great amount of water through perspiration and must drink more often. It is important that you identify dehydration as quickly as possible, as the horse can die or suffer from colic if the condition isn't rectified.