A horse is 'off' when the stable has a horse that they expect to win (ie in good form against weaker opponents & with right going, distance etc) AND their and the owners money is put down supporting it in the market
Cannon Fodder drifted all day in the betting and was outside first 3 of just 6...
I know someone also that ought to know who says it's not off.
Drifting all day on Betty, a LOT of local money follows this when fancied, watch the price