A trainer "attached" to Sheffield's Owlerton Stadium, who regularly races greyhounds there, has been charged with offences by greyhound racing authorities after one of his dogs tested positive for cocaine. Stuart Mason, who trains greyhounds at kennels near Wakefield, faces a Greyhound Board of Great Britain inquiry after it was confirmed that his dog Droopys Arshavin tested positive for cocaine and its metabolite benzoylecgonine following a race at Wimbledon on August 3rd, writes Greyhound Watch.