I WAS recently asked by one of the staff here at Mark Johnston Racing whether racehorses could have heart attacks and, if so, could they be a cause of sudden death during exercise. The scientific answer is: No.

The term “heart attack” has incorrectly evolved into referring to sudden death associated with heart disease. In human medicine, the term refers to myocardial infarction (coronary heart disease) caused by clogged blood vessels which reduces blood flow to the heart muscle itself. The result is damage to, or death of, the heart muscle, which can cause functional failure of the heart and death of the individual. Because horses are herbivores and, unlike humans, do not suffer from coronary artery disease, heart attacks in their true definition rarely occur.