Trainers have often believed that heart size has played a huge role in racehorse performance. As science improved it has been proven to be true. I won’t go too much into the science of it all, but will give you some examples. In Thoroughbred horses, heart mass is roughly 1% of overall body mass. This means most TB’s have a heart mass of 4-5kg. In other breeds the heart mass is less than 1% body mass. However, some famous racehorses had much larger hearts:
Secretariat, 1973.
Famous for winning the American Triple Crown with incredible style. Secretariat is one of the most well known examples of a hugely successful racehorse with a huge heart. He had a heart mass >10kg, one of the largest hearts found in racehorses.
Sham, 1973.
Secretariats only true rival for the Triple Crown and one of the best horses of the time. He also had a huge heart mass of 8.2kg.
Sham. Credit, Horse racing Nation
Key To The Mint, 1972.
American Champion 3 year old and brilliant Broodmare Sire. Had a heart mass of 7.2kg.
Phar Lap,
Famous Australian racehorse. He had a heart mass of 6.4kg,
Phar Lap
This is not an extensive list. There are so many other world famous racehorses who may have also had larger hearts, including: Red Rum, Seabiscuit, Arkle and Man O’War. It may be that there was never an autopsy so no record of their heart size. But wouldn’t it be interesting to find out?
Last Updated on 05/12/2021
