Illness has ended apprentice Harry Coffey's day at Caulfield after just one ride.

Coffey, who has cystic fibrosis, is equal with the injured Patrick Moloney and leading Katelyn Mallyon by three wins in the race for the apprentices' premiership.

He had a book of seven rides at Caulfield on Saturday but struggled to hold Miss Yearn in the Chase Hotel Handicap, prompting doctors to examine him.

He was stood down from his remaining rides at the meeting.

Steward Rob Montgomery said Coffey was scheduled to visit a specialist on Thursday.

But Coffey's illness is likely to cause the jockey to bring the appointment forward.