CNN’s review only included horse deaths that were required to be reported to state commissions, so it undercounts the total deaths associated with individual trainers.

Source: https://krdo.com/news/national-world/cnn-national/2023/06/10/as-horse-racings-best-trainers-rake-in-millions-records-show-theyve-violated-rules-aimed-at-keeping-the-animals-safe-2/