Multiple Group One winner St Nicholas Abbey has suffered a setback in his fight to recover from life-threatening injury and illness.

The Aidan O'Brien-trained winner of six Group Ones suffered a fractured pastern in July and was also treated for colic.

He had a further setback in August when it was discovered a steel weight-bearing pin in a cannon bone had broken and this week owners Coolmore reported he was suffering from mild laminitis.

"St Nicholas Abbey has suffered a setback over the last 24 hours having developed mild laminitic changes in the left fore," Coolmore said.

"This is disappointing as he is now weight bearing and walking well on the operated (fractured) leg which has healed amazingly well to date.

"Although laminitis could be a life threatening complication we are hoping the condition will stabilise.

"Obviously the next weeks are critical in his recovery but St Nicholas Abbey remains comfortable with a good appetite and incredible attitude."