Backs Adam Hughes, Aled Brew and Ashley Smith crossed for tries in the first half as the hosts broke into a 19-3 lead.
Italy tly-half Kris Burton got a converted try back for Treviso, but further tries from Brew and Will Harries sealed a bonus point win for the Dragons.
However, the result was tempered for the Welsh region by the suspected rib cartilage injury picked up by stand-in captain Luke Charteris.
The Dragons, who lost at home to Leinster last Sunday, looked quite comfortable by the break after a pretty low-key first half hour.
The teams were only separated by a ninth try of the season from centre Hughes, who went over when the ball ran loose on the left as Tom Riley and full-back Martyn Thomas pressurised the Treviso defence.
From there, Hughes hacked on to the line and stretched high to beat defender Gonzalo Garola to the ball.
Centre Smith came on when Thomas, who has only been back since late January from a nine-month leg injury absence, limped off with another leg problem.
Smith, back after a month out with a shoulder injury, immediately had an impact as he made one try and scored another to give the Dragons a 19-3 advantage at the break.
Firstly, faced with being put into touch on the right while inside the Treviso 22, he cross-kicked to the middle of the field with the outside of his boot to put winger Brew over.
And when a hole appeared in the Treviso defence in the 38th minute, number 8 Toby Faletau went through to set his team-mate up for a run in under the posts.
Burton opened Treviso's account in first half injury-time with a penalty from 25 metres out, but it was still a long way back for the Italians.
However, they came out fighting at the start of the second period and were rewarded when Burton took a pass from a ruck and went through Wayne Evans and Jason Tovey from five metres out to score near the posts, adding the conversion for good measure.
Burton could have reduced the arrears further but his penalty in the 48th minute struck a post and after a flood of replacements from both coaches, the Dragons regained control.
Treviso captain Antonio Pavanello clash with Dragons replacement Gavin Thomas and got away with a warning when a card looked probable.
And the visitors' hopes of a comeback win were soon extinguished as the Dragons went up a gear in the final quarter.
Smith and Tovey combined to send Brew over for the bonus point try, and moments later Tovey's chip over the defence was caught by winger Harries who had a 40-metre sprint to the line.
Adding to their frustration, Treviso finished the game with 13 men after replacement Gonzalo Padro was sin-binned for pushing Evans to the ground, and prop Diego Vidal saw yellow for dangerous play.
|Newport Gwent Dragons Score Card|
|Benetton Treviso Score Card|