DEL MAR, Calif. – The California Horse Racing Board voted on Thursday to reduce the permitted levels of the anti-inflammatory analgesic phenylbutazone, a common medication known as Bute, effective Jan. 1.The board delayed implementation to give trainers time to adjust to the new guideline, which reduces the permitted level from 5 nanograms per milliliter of blood to 2 nanograms. The rule change will mirror a policy by the American Graded Stakes Committee that takes effect on Jan. 1, 2012 requiring all graded races nationwide to have a 2 nanogram threshold. The lower threshold also has been approved by the Racing Medication and Testing Consortium and Racing Commissioners International.The racing board approved the measure by a vote of 4-3, with chairman Keith Brackpool and commissioners Bo Derek, John Harris and Jesse Choper voting in favor. Vice-chairman David Israel and commissioners Jerry Moss and Richard Rosenberg voted against the rule change.The measure was supported by the Breeders’ Cup and the Jockey’s Guild, with opposition from the Thoroughbred Owners of California and California Thoroughbred Trainers.Veterinarian Don Shields spoke in opposition of change, saying that the current level of anti-inflammatory on racedays is “well below the clinically active dosage.”According to racing board statistics, 85 percent of the horses tested in the first three weeks of the 2010-2011 Santa Anita winter-spring meeting tested below the 2 nanogram level.Brackpool spoke in support of the change. “I’m not hearing many comments that it will be bad from the horse to go from 5 to 2 [nanograms],” he said.The racing board also changed a rule that will void a claim if a claimed horse suffers a fatality during the running of a race or before it is returned to be unsaddled. The rule change was approved by a vote of 5-2, with Moss and Rosenberg in opposition.The rule change must be reviewed by the state office of administrative law before taking effect. Racing board executive director Kirk Breed said the rule change could be implemented in a “month or two.”According to racing board statistics, six horses that were the subject of claims at California tracks, other than Los Alamitos, suffered fatalities during races from Jan. 1, 2007 through Sept. 1, 2010.