William Haggas' dual Group One winner had her career brought to a premature end when she had to undergo surgery for the problem last week.
While there has been minor improvement in her health, the filly is still seriously ill.
Haggas told Racing TV: "She's what they call critical but stable, but possibly not as critical as she was, according to this morning's report.
"They always say the nice things, but then say 'she's still not out of the woods yet'.
"She's bright in herself, she's so tough and genuine, but she's weak. Her immune system is very low so she's liable to any possible infection.
"It's awful to see, as people who have seen it before know, but this is such a special filly."