This afternoon, the mare's veterinarians performed what the farm called a "surgical procedure...to drain an abscess discovered this morning".
"Though her road toward recovery remains remarkable following abdominal surgery performed on February 13th, this is an important reminder that challenges remain," the farm statement read.
"As part of the continuous evaluation and monitoring that Rachel is receiving at Rood & Riddle, an abscess adjacent to her reproductive tract and rectum was found this morning," said Dr. Brett Woodie.
The surgery was performed as a standing procedure; the hospital reported that her vital signs had remained normal during the procedure.
Stonestreet Farm stated that Rachel Alexandra was also "bright and alert with a good appetite following this procedure and was even able to graze this afternoon."
"While this type of hurdle is not unexpected, Rachel will remain at Rood & Riddle for continuous observation as she continues down what has been called 'a long road' toward recovery,". the notice ended.
Rachel Alexandra was hospitalized last month after giving birth to a filly, who is now with a nurse mare. ?Surgery to repair an intestinal injury suffered during the birth was deemed successful, and the mare has been recovering at the hospital in the interim.