There will be no exemptions for the horses returning Ibuprofen positives in recent months with Racing Victoria saying the rules must apply.
The high profile Signoff, fourth in the 2014 Melbourne Cup, returned a positive test to the anti-inflammatory after winning the Lord Stakes at Caulfield last December.
In the lead-up to the race, trainer Darren Weir had taken elective tests which were negative.
Signoff and a number of other horses have been treated with Ibuprofen on a property in Victoria as part of their rehabilitation from tendon injuries.
The RV Integrity Council said there was no legitimate case to allow any exemptions.
“We sympathise with the owners of the small group of affected horses from the one rehabilitation regime, however Racing Victoria is committed to enforcing the Rules of Racing by governing a sport which sees all horses race free of the effects of drugs,” RV chairman of stewards, Terry Bailey, said in a statement.
“We understand that the use of this substance for the treatment of tendon injuries in racehorses is a complex issue because of prolonged and unpredictable clearance of the drug so we have explored all available options for the affected connections.
“However, the parent drug Ibuprofen is being detected in samples obtained from these horses at levels that make it impossible to differentiate between a recent treatment and a level caused by the leaching of the substance from a tissue storage site.”