In the May 26 article by Dave Briggs entitled Why the AGCO Lowered the TCO2 Test Threshold there are a number of points that need to be addressed and corrected.
There is no doubt that the main reason for the decision to lower the testing threshold was “mostly a matter of aligning itself” with other racing jurisdictions. That does not mean they have the science right – they are merely doing what everyone else is doing – rightly or wrongly.
The AGCO release regarding the ‘natural level’ of TCO2 in blood is inaccurate, and based on averages, not the actual values in scientific research studies, including those studies supported by horse racing jurisdictions. The normal range, as reported in scientific studies that have been peer reviewed by other scientists, is 23 to 38 mmol/L, not 26 to 32 mmol/l (see below for a selection of these studies). The range for the ~99% of horses is from 25 to 35 mmol/l. There are no scientific studies, reporting values from individual horses, that have reported a range as narrow at 26 to 32 mmol/l.