Trainer Erwin Takacs has undergone brain surgery in Wollongong Hospital after a mystery accident at Kembla Grange.
The 64-year-old's condition was listed as critical on Monday and he was on life support.
Takacs was found unconscious near the swimming pool at the training centre on Sunday but there were no known witnesses to the incident.
The horse he was tending was captured with a swimming pole still attached.
Racing NSW's Dr Ron Muratore reported Takacs had had an intracranial haemorrhage and the prognosis was "guarded".