United currently has a seven-point lead at the top of the table, ahead of second-placed rival Manchester City, but Ferdinand admitted the title race was far from over.
With just six matches remaining of the 2011-12 season, United had an eight-point edge over City, but conspired to lose the title on the final day of the season.
"Last year it was new because it was the first time they had challenged properly and there was a lot of focus on Manchester," Ferdinand told reporters.
"But we have to make sure we keep our own house in order, make sure we keep ticking off the games. We don't have to focus on anyone else, just ourselves."