David Jacobson, one of the top claiming trainers of the mid-2010s, has been suspended 30 days by the Horseracing Integrity and Welfare Unit after one of his horses tested positive for an excessive amount of total carbon dioxide in the blood, according to HIWU records. The 30-day suspension began on Thursday. HIWU said that Jacobson had admitted to the violation and accepted the penalty, which also included the disqualification of the horse Got Thunder from a second-place finish in a March 21 allowance race at Penn National. Horses are typically tested for total carbon dioxide by pulling a blood sample prior to a race. Since horses have a natural amount of the gas in their blood, HIWU and other regulators use a threshold for the amount of total carbon dioxide that can appear in the sample before calling a violation. An excess of total carbon dioxide is typically due to a horse being administered bicarbonates prior to a race, which can reduce the build-up of lactic acid in muscle during intense exercise. Thoroughbred racing began cracking down on the use of bicarbonate solutions in the late 1990s when it became apparent that many horses were being administered so-called “milkshakes” pre-race through a nasal gastric tube. Jacobson, who owns many of his horses, posted career highs in wins and earnings in 2014, when he won 199 races from 826 starts and had $8.4 million in purse earnings. In a six-year period from 2010-2016, Jacobson’s horses won at a rate of 20 percent or better. Jacobson, the son of controversial trainer Howard "Buddy" Jacobson, was out of the sport for nearly four years beginning in 2018 due to health issues. He resumed training in 2022. For his career, Jacobson has won 1,393 races from 7,348 starts, with purse earnings of $52.4 million.  :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.