Course officials took the early decision after a waterlogged area of the track had not shown the required improvement overnight and more rain is forecast.
When Friday's card was called off shortly after 7pm on Thursday, an inspection was called for noon on Friday to assess conditions ahead of the big meeting, but that was brought forward.
As a result, it means the whole three-day fixture on the west coast of Scotland has been called off.
Clerk of the course Graeme Anderson said: "We have a false patch of ground around two and a half furlongs out and it is just not improving.
"It is just mud and moving around, it's not safe.
"If it was an isolated patch we could move rails to avoid it but it's halfway across the track.
"It hasn't improved and we're forecast up to six millimetres of rain today.
"People are talking of Sunday but before we get into the logistics of that the forecast for Sunday is even worse.
"It's not warm, there's barely a breeze so the four hours between now and noon wouldn't make a difference."