Letter: What's killing the race horses in the USA?

Are there any Federal and/or State laws that can be used to investigate the business of horse racing in the US? Race horses are dying in unprecedented numbers. There are obviously one or more reasons why. Perhaps it is just a coincidence that so many of those that have died have been trained by one particular trainer. A trainer that has previously been temporarily banned because his horses did not pass drug tests. The deaths need to be thoroughly investigated…and perhaps new laws need to be written. Or perhaps old laws need to be enforced. Broken laws need to be litigated. These horses need to be protected. Maybe the "sport" needs to be halted until these actions have been completed.