No jockeys in Ireland have tested positive for banned substances since widespread random testing was introduced, according to the Turf Club.
Random testing has been in operation on both sides of the Irish Sea for several months. On Monday, Mr Keith Dalgleish became the first jockey in Britain to fail the tests since they were introduced on a much more regular basis than before.
The tests are part of a crackdown on drug and substance abuse. The jockeys' legal alcohol limit is 17 micrograms per 100 millilitres in breath - about half that for driving and similar to that of safety-sensitive jobs in other industries.
Mr Dalgleish took two tests at Redcar racecourse and failed both. The Scots jockey was stood down for the day by the stewards for "safety reasons".
If a urine sample confirms the breathalyser results, he will face disciplinary procedures and a possible six-month riding ban.
Mr Dalgleish is in the top 20 in the jockey's table, having ridden 56 winners this year.
The press officer of the Turf Club in Ireland, Mr Cliff Noone, said no jockeys at race-courses in Ireland had tested positive for banned substances.
"We have received the results back from the batch of tests for the first six weeks and they have all been negative," he said.
Mr Noone said the regulations for jockeys regarding banned substances were in line with those for participants in other sports. The Turf Club had invited Irish jockeys to a seminar earlier this year at which the guidelines were drawn up, he stated.
"It's not just about illegal drugs and alcohol. Some medications also contain prohibited substances. Jockeys have to be very careful. They could be taking medicine for the flu, or using an inhaler, and unwittingly be taking a banned substance."