Born and raised in Montreal, he played college football in the United States for the California Golden Bears.

He signed as an undrafted free agent with the New Orleans Saints in 2005, before joining the Cowboys that same year.

Ladouceur was selected in the fourth round of the 2004 CFL Draft by the Ottawa Renegades, but decided to return to school.

[4] Ladouceur was signed as an undrafted free agent by the New Orleans Saints after the 2005 NFL draft on April 27.

[10] He tied the franchise record of playing in 16 seasons, shared with tight end Jason Witten.

On December 20, he played in his 251st career NFL game, moving him past kicker Eddie Murray as the most ever by a Canadian-born player.