Ferniehirst's place in the $500,000 Country Championship final is in doubt with a swab taken from the mare before her qualifying run found to contain the anti-inflammatory naproxen.
Trained by Paul Smith at Coffs Harbour, Ferniehirst ran second to Snitz in the Northern Rivers heat of the Country Championship to earn a place in Saturday's race at Randwick.
Racing NSW stewards will hold an inquiry at Coffs Harbour on Thursday.
Ferniehirst is at $31 in latest markets with Suncraze and Don't Give A Damn sharing $4.20 favouritism.
- Smaller Small Medium Big Bigger
- Default Helvetica Segoe Georgia Times
- Reading Mode