Two late goals from Norwich City saw Spurs knocked out in the fourth round of the competition and Dawson has admitted that it was difficult to come to term with the loss.
The defender told the club's official website: "It's hard to take. It's never easy to lose any football match but the way we lost this one makes it tough.
"We had all of the possession in the first half and I don't think Norwich had a shot at goal.
"Norwich got a goal from absolutely nowhere and it gave them momentum. To be out of a cup that we've had good runs in over recent years is disappointing."
Spurs turn their attentions back to the Premier League on Saturday when they host Wigan Athletic.