The Riders also acquired Dubuque's eighth-round pick in Phase II of the 2014 United States Hockey League draft and gave up a fourth-round pick. Gaus, 18, will take the spot of forward Nick Master on the active roster.
Master suffered a broken fibula in a game last Saturday and is out for the season.
Like Master, Gaus is a Pennsylvania resident. The Yale University commit has two goals and two assists in 20 games this season with a plus-minus rating of minus-seven.
Prior to joining Dubuque, he played at The Taft School in Connecticut. The RoughRiders play Friday night at Dubuque and host Indiana on Saturday night.