Kentucky&rsquo;s stewards have rescinded the penalties they handed down last week to the trainers Rusty Arnold and Joe Sharp after Kentucky Horse Racing Commission personnel raised doubts about the validity of positive test results for ractopamine from nearly 18 months ago, according to racing commission officials.The penalties were rescinded after commission personnel talked Monday with the director of the state testing laboratory over the positives, according to Marc Guilfoil, the executive director of the commission. The director, Dr. Rick Sams, said that he did not feel the positives would withstand a court challenge, according to Guilfoil.&ldquo;He&rsquo;s the expert,&rdquo; Guilfoil said, referring to Sams. &ldquo;The only thing we could do was the right thing to do.&rdquo;Arnold was facing a 90&#45;day suspension for two positives for ractopamine in horses that ran at Kentucky Downs in September of 2016. Sharp was facing a 30&#45;day suspension for a positive for one horse that ran at the same Kentucky Downs meet. Both trainers would also have had to transfer their horses to other trainers during the terms of the suspensions in order for the horses to be eligible to race.Arnold had said in interviews last week that he intended to appeal the penalty. He said that he had not administered ractopamine, a common feed additive for livestock, to any of his horses at any time in his career, and he claimed that the positives could only be the result of environmental contamination.On Wednesday morning, Arnold said he was glad that the matter was behind him. &ldquo;I&rsquo;m very relieved that I&rsquo;ve gotten this off my shoulders,&rdquo; Arnold said. &ldquo;It&rsquo;s been trying. But in the end the commission did the right thing.&rdquo;Arnold also said that he had no plans to pursue claims against the commission through a civil suit.&ldquo;I&rsquo;ve got nothing but respect for the people on the racing commission,&rdquo; Arnold said. &ldquo;I wish the system wasn&rsquo;t broken a little bit and that my name got dragged through the mud.&rdquo; Ractopamine is a Class 2 drug that has a higher classification rating for determining penalties. The drug is used to build lean muscle mass in livestock, and is typically administered on a regular basis. Guilfoil said that the drug itself was not found in the original samples. Instead, tests on the samples indicated the presence of metabolites of the drugs, and, under Kentucky rules, that would not be sufficient to call a positive, according to Guilfoil.Guilfoil said that he spoke with both Arnold and Sharp on Wednesday morning to apologize.&ldquo;Part of [the phone call] was that I wanted to apologize, and part of it was that if they wanted to jump on me a little bit, here&rsquo;s the opportunity,&rdquo; he said.