How do I tell if my horse is drinking enough water during hot weather?

A horse's water intake increases significantly in heat, and dehydration develops faster than most owners expect during hot weather or heavy work. The baseline requirement for a horse at rest in moderate temperatures is roughly 5 to 10 gallons per day, but that number rises sharply with temperature, humidity, and work intensity. The most reliable field check for hydration is the skin turgor test: pinch the skin on the neck or shoulder, release it, and watch how quickly it snaps back. In a well-hydrated horse, it returns immediately; if it takes two seconds or more, the horse is dehydrated. The gum capillary refill test is equally useful: press your thumb firmly on the gum above the upper teeth, release, and count how long it takes for color to return to the blanched spot. Normal is under two seconds. Beyond these tests, observe water consumption directly if possible: a horse that is avoiding the trough in heat is a concern, and the reason might be water temperature (horses prefer water that is not scalding hot from a sun-exposed trough), algae or contamination, or illness. Electrolyte supplementation during heavy work encourages drinking and replaces minerals lost through sweat, but it should accompany adequate plain water access, not replace it.