Hill ‘n’ Dale Farms announced that their elite sire Curlin, a 22-year-old stallion and multiple Horse of the Year winner, will cease covering mares for the remainder of the breeding season due to a suspected low fertility issue. After successfully breeding 25-30 mares earlier in the year, a significant drop in pregnancy rates was observed in subsequent mares. Veterinary evaluation confirmed the fertility problem, leading to the difficult decision to pause breeding to allow Curlin time to regenerate semen. Additional health concerns, including an unusual ulcer and a fever, were noted but their connection to the fertility issue remains unclear.

Curlin, who has been a top North American sire since 2015 with 118 black-type stakes winners and multiple graded stakes champions, had been booked to 97 mares this year. Hill ‘n’ Dale emphasized the importance of transparency with breeders and expressed hope that Curlin could return to stud duty next year after recovery. Despite the setback, the farm acknowledged Curlin’s significant impact on the breed and his valuable contributions to their program and the broader racing community.