A member of Khalid Abdullah's European racing team is to meet with The Jockey Club to discuss its drug testing procedures after two Juddmonte horses were disqualified from group I races for testing positive for clenbuterol, a treatment for viral respiratory conditions.The most high profile of those cases concerned Three Valleys, the impressive Royal Ascot winner and the joint fourth highest-rated European juvenile in 2003. The son of Diesis was disqualified from last October's Shadwell Stud Middle Park Stakes (Eng-I) at Newmarket.That came after the Abdullah-owned Tillerman, from a different stable, was demoted from second to last in the Queen Anne Stakes (Eng-I) at Royal Ascot on June 17 after testing positive for the same substance, which has a trade name of Ventipulmin.Unlike the set threshold levels found in American racing, Europe has a zero tolerance approach for clenbuterol."It is important to know the actual quantity involved in these tests," Teddy Grimthorpe (formerly Teddy Beckett), Abdullah's European racing manager, told The Blood-Horse.That issue is also of concern to the National Trainers' Federation, whose chief executive Rupert Arnold, said: "It is something we are very keen to explore with the Jockey Club." Arnold said trainers had raised a number of frustrations with him about drug testing procedures, particularly for substances like clenbuterol which are subject to a zero tolerance policy. Concerns include the fact that positive test levels aren't revealed, leaving trainers in the dark as to whether they can avoid a problem in the future simply by withdrawing a treatment from a horse a day or two earlier. The NTF also wants clearer and more accessible guidelines from the Jockey Club as to how many days a treatment should be withdrawn from horses before they race. "This whole issue is very much of a concern to us and you have to ask how trainers can run their business without knowing what a safe amount of withdrawal time is," Arnold said. "The curious thing about withdrawal times is that the Jockey Club has said it is not prepared to make available its booklet on the subject to trainers." Grimthorpe will meet in early February with Peter Webbon, the Jockey Club's chief veterinary officer, to discuss his concerns.High on the agenda will be how Three Valley's tested positive for clenbuterol in the Middle Park but not in the Dewhurst Stakes (Eng-I) 15 days later, even though trainer Roger Charlton followed the same guidelines and withdrew Three Valleys from treatment within the same period.The Jockey Club guidelines suggest clenbuterol should not be used less than six-and-a-half days before a race.Aware of controversies in other sports, Grimthorpe said: "We would like to establish exactly what process The Jockey Club is looking to in terms of all drug testing and in terms of clenbuterol to try to devise a reasonable line of withdrawal."Grimthorpe added clenbuterol, when used in a powder form, was a "fairly volatile substance" whose traces could easily contaminate a horse through a number of innocent ways. That is why he is keen to establish the levels of the substance found in Three Valleys and Tillerman.There were a number of similar cases to those horses in England last year, prompting calls for the recommended withdrawal period to be extended from 6 1/2 days to 10-14 days. But Grimthorpe said, "If you extend the withdrawal period that far you start to ask how useful it is."An extension of the withdrawal period is unlikely, according to the Jockey Club's Webbon, who said, "In 2000, the major racing countries got together and established that there was a six-and-a-half-day detection period for clenbuterol when administered orally."There is no reason to change that, it's a fact--but how you turn that guideline into a withdrawal time is for trainers and their vets to work out. It is an important subtlety and a difficult call for trainers to have to make, especially as it clearly takes longer for some horses than others, especially when they have been given a relatively long period of treatment."Nobody is pretending that it is an easy decision to make. It is a difficult balancing act to keep your horse on the treatment for as long as possible and as close as possible to the race without breaching the rules."While the Abdullah camp is concerned about the positive tests, it is highly unlikely that this could lead to a withdrawal from British racing in protest, similar to the Aga Khan's self imposed boycott of British racing as a result of his Oaks (Eng-I) winner Aliysa being disqualified for testing positive for camphor."Our main aim is to get healthy horses to the races and the main thing we want to do know is to look forward to the future and try to establish ways of avoiding such problems," Grimthorpe said.Despite Three Valleys' disqualification, Abdullah was still crowned champion owner in Britain last year with winnings of £1,796,464.