Champion filly Songbird has been retired five days after she lost for just the second time in 15 career starts.
Owner Rick Porter of Fox Hill Farm said Thursday that he made the decision after an examination showed an enlargement of both of the 4-year-old filly's hind suspensory ligaments.
Porter said it would be dangerous for Songbird to continue training and veterinarian Larry Bramlage wasn't optimistic that the situation would improve in time.
Last Saturday, Songbird lost by a neck to longshot Forever Unbridled in the Grade 1 Personal Ensign at Saratoga. Her season debut had been delayed while she recovered from bone bruising last winter.
Songbird had 13 wins and two seconds in 15 career starts and earnings of $4,692,000. She won Eclipse Awards as champion 2-year-old filly in 2015 and champion 3-year-old filly last year. She was trained by Jerry Hollendorfer and ridden by fellow Hall of Famer Mike Smith.
She won 11 straight races in her first two seasons on the track. She won the 2015 Breeders' Cup Juvenile Fillies and finished second to Beholder by a nose in last year's BC Distaff.
''She meant a lot to every single person in the stable, from the grooms and hot walkers on up to the trainer,'' Hollendorfer said.