Clydesdales generally live into their late teens to early twenties.
Tooth examination is one of the most reliable methods for aging a horse. As a horse ages, the tablelike surfaces on the teeth gradually wear down. The front teeth will tend to bow out toward the lips.
As Clydesdales reach their middle teens some develop more white on their faces.
Colic - sharp abdominal pains and flatulence are often symptoms of an obstruction created by a mass of hard food or feces in the bowel, which can lead to twisted intestines and death.
Calcified materials called entroliths can cause gut blockage and death.
Domestic horses often die of old age. Their hearts and kidneys often fail.