Detection of bicarbonate administration (milkshake) in standardbred horses.

The research investigates the normal TCO2 levels in standardbred horses in order to identify abnormal elevations in these levels that might point to the illicit practice of bicarbonate administration (milkshaking) to enhance performance. It further presents a comparison of two types of analysers used in measuring TCO2 levels, and the potential variations they could cause in the readings.

Measuring TCO2 Concentrations

• The study measured Total Plasma Carbon Dioxide (TCO2) levels in a selection of Standardbred horses that were both stabled and soon-to-be raced. The measurements of these two groups differed, with the pre-race horses showing an irregular distribution of TCO2 values.
• Using these findings, the research was able to establish a mean normal TCO2 concentration of 30.2 mmol/L with a standard deviation of 1.2 in resting horses, providing a basis for identifying aberrations that might indicate ‘milkshake’, bicarbonate administration.

Detection Criteria for Milkshaking

• The study provides an estimation that about 50 horses out of one million are likely to show TCO2 measures of greater than or equal to 35 mmol/L, an elevated level.
• It also signifies that it is highly unlikely for a horse at rest to show a reading beyond 36 mmol/L.
• The sensitivity of these values, which denotes the proportion of actual positives correctly identified, was found to be 67% and 59% respectively and with 100% specificity, indicating the absence of false positives.

Variations in Stored Blood Samples

• The research also discovered that TCO2 levels in blood samples remain relatively stable for up to 4 days when stored at 4 degrees Celsius, but decline progressively over a course of 5 days in samples stored at room temperature or ambient temperature. This discovery has implications in sampling and storage practices when detecting bicarbonate administration.

Beckman EL-ISE and Kodak Dry Chemistry Analyser

• The research used two types of TCO2 analysers, the Beckman EL-ISE and the Kodak Dry Chemistry Analyser, to compare their readings.
• While values obtained from both devices were not significantly different, the results from the Kodak Dry Chemistry Analyser averaged 0.5 mmol/L more than those recorded by the Beckman EL-ISE.
• This raises questions about the potential variations caused by these machines and their significance in the testing of horses for milkshake administration.