All fixed odds racing bets are subject to deductions. This is because when a horse is removed from a race, the percentage chance of another horse winning increases, and the previous odds are no longer a fair reflection of the market situation.
The calculation is expected payout x (100 - deduction) / 100. So if you bet $10 on a horse to win at $7.00 but suffered 15c deductions, the calculation is:
$70 x (100-15) /100 = $59.50.
You can see scratchings and deduction amounts from the individual race page and the full deductions table is contained at clause 4 of our our Betting Rules - https://www.playup.com.au/Rules