Dixon had an eventful summer, leading the Cowboys with 12 tackles in their preseason opener against the San Diego Chargers, showing up late to a walk-through that left him benched for the second preseason game and earning a $22,050 fine for hitting a defenseless receiver in the third preseason game.
If Dixon clears waivers, he could be brought back to the practice squad.
At the time Dixon was drafted, the Cowboys hoped he would develop into a special teams' ace, but they opted to keep Jemea Thomas, who was claimed off waivers from the New England Patriots last week, and go with Spillman, who led the San Francisco 49ers with 19 special teams' stops in 2013.
Dixon was one of the Cowboys' five seventh-round picks and the third to be cut, joining Will Smith and Terrance Mitchell. Ben Gardner is on injured reserve with a shoulder injury. The only seventh-rounder currently on the 53-man roster is defensive tackle Ken Bishop.