A dramatic day of racing at Sandown was brought to a halt after three races on Wednesday when the racetrack was declared unsafe.

Jockeys riding in the flat races at the meeting first had concerns over horses slipping during the third event - the first on the flat.

Racing officials quickly had the section of track aerated and that looked set to save the meeting.

That was until another problem surfaced with divots, which had not consolidated after remedial work, was raised by champion jockey Glen Boss who had walked the track with trainer Mick Kent.

The Sandown rail position was originally going to be 15m out but when the Melbourne Racing Club agreed last week to host two jumps races which could not be staged at Moe, the rail placement had to go into the 13-metre position.

"The problem coming into today was we were shifting the rail back in to where we didn't want it because of the jumps racing and I was always fairly nervous leading into today that the inside two (metres) wasn't going to be great," track manager Tim Bailey said.

"And we've been bitten on the bum".

Racing Victoria steward Rob Montgomery abandoned the meeting after the first flat race.

"Unfortunately there is still some plug divots where they repair the track and they haven't taken. They can be pulled out with the hands," Montgomery said.

Boss said it was unsafe to continue racing.

"You'd be unlucky to hit one, but if you do hit one it would be very unsafe for your horse and rider," Boss said.

The Sandown track re-opened earlier this year after a renovation.

Bailey does not see any issue with upcoming Sandown meetings going ahead.

The meeting was marred by a horse fatality in a steeplechase race - the opening event of the day - which had to be abandoned mid-race.

Show Dancer appeared to slip as it prepared to jump one of the obstacles early in the 3400-metre event and crashed through the jump.