Global concern: Curlin stops covering due to a fertility issue

The outstanding stallion, a pillar of modern breeding, was withdrawn from stud duty mid-season in a decision as difficult as it was necessary

PARIS, Kentucky (Special to Turf Diario).- The news shook the global breeding industry: Curlin, one of the most influential stallions of the 21st century, has been withdrawn from stud duty for the remainder of the season after a fertility issue was detected.

The decision was made by Hill 'n' Dale Farms at Xalapa after a noticeable drop in pregnancy rates among mares covered during the second part of the breeding season became evident in recent days. A final evaluation, conducted by renowned specialist Dr. Dickson Varner, recommended the immediate suspension of his activity.

“We have a large enough sample of barren mares to confirm the situation. He will need to regenerate semen, and that takes time,” explained John Sikura, president of the farm, when announcing a decision that directly impacts the season.

The 22-year-old son of Smart Strike had covered between 25 and 30 mares normally at the beginning of the year, but the situation changed abruptly in the second book, raising concerns.

The issue has been accompanied by some recent physical setbacks: a fever—reaching 102°F—and the detection of an ulcer in an unusual area. While no direct connection has been confirmed, the farm has not ruled out that stress and a combination of factors may have affected semen quality.

“Perhaps all of that impacted the sample. We hope he can regenerate for the next cycle and return in 2027. We will be very cautious,” Sikura added.

Beyond the immediate implications, the news raises questions about the future of one of the pillars of modern breeding. Because speaking of Curlin is speaking of sustained excellence: a two-time Horse of the Year on the track, more than $10.5 million in earnings, and, at stud, an extraordinary legacy with 118 stakes winners, 68 of them graded, and 11 champions.

His influence has been constant, ranking for years among the leading sires in the United States and leaving a deep imprint on the Breeders’ Cup, with multiple winners in recent seasons.

But this time, the focus is elsewhere.

“We preferred to make a quick and fair decision for breeders rather than wait and harm those who entrusted us with valuable mares,” Sikura explained, also highlighting the full support of partners and key figures such as Barbara Banke.

The impact is significant. Curlin had approximately 100 mares booked for this season. And while hopes are set on a recovery for next year, the message was clear: right now, the horse comes first.

“If he can come back for one or two more years, that would be fantastic. And if not, he has already been a blessing to the breed,” Sikura concluded.

In a world where great stallions define eras, Curlin’s pause leaves an immediate void—and a certainty: his legacy is already secure.