May take several days to show up after a ride, and in severe cases is life threatening. The longer the time, the greater the dehydration of the horse. Over three to four seconds indicates potentially serious dehydration. To be accurate on endurance horses, this test should be applied at the point of the shoulder, not up on the neck. Caused by electrolyte imbalance.
Vets observe the horses as they pass, primarily for lameness.
An emergency requiring immediate veterinary care, and not moving the horse. Not to be confused with cramping, which occurs after many miles of stress. A checkpoint along the trail where the horses are examined by ride veterinarians to determine their fitness to continue. See Chapter Nine.