Dana,

You can find a detailed description of the testing and procedures the BC has committed itself to beginning on page 80 of the guide linked below. I'm not aware of any independent means to verify that they are being done. The routine is supposed to include daily inspections of an entrant; TCO2 testing on every entrant; out of competition testing (for which substances??) and post-race testing performed on at least the first four finishers in any BC race.

https://members.breederscup.com/doc%20repository/other/hig.pdf