Tom Ryder touched down soon after the restart to extend the Warriors' lead and man of the match Niko Matawalu set up Seymour to go over in the corner for the bonus point just past the hour.
A successful chip and chase gave Seymour his second try with Scott Wight converting for a 37-6 lead, taking his personal haul to 12 points for the night with three conversions and two penalties, condemning the Dragons to a third defeat on the bounce.
The Dragons retained possession early on but the Warriors won a penalty at the breakdown with Wight landing it from near the halfway line to open the scoring after five minutes.
Murchie soon went over for the first try of the match with the ball hacked through and the 26-year-old sharpest to react, Wight adding the extras to give the Warriors a 10-0 lead after a quarter of an hour at Scotstoun.
With only 17 minutes gone the Dragons were forced into two changes, captain Lewis Evans going off for Jevon Groves while Adam Jones came on for Robert Sidoli.
A high tackle gave the visitors a chance to reduce the deficit after 24 minutes but Lewis Robling's penalty from the halfway line slid wide of the posts.
It got worse for the Dragons just before the half-hour mark when Warriors loosehead Reid picked up and went from the base of the ruck from outside the 22 to burst through under the posts, with Wight converting for 17-0.
However the Dragons finally got off the mark in the 31st minute with Prydie landing an easy penalty for offside at the breakdown just outside the 22.
Three minutes later though Wight added to his tally with another penalty after the Dragons had been pulled up for a scrum infringement to restore the Warriors' 17-point lead.
Darren Edwards was forced into a third first-half change with Phil Price going off for Nathan Williams four minutes before the break, but another Prydie penalty in front of the posts reduced the arrears to 20-6 at half time.
Straight after the break the Warriors' pack began to pile on the pressure inside the Dragons' 22 and Ryder pounced as his side piled over the line for the hosts' third try three minutes into the second period, though Wight missed his conversion this time to leave the scores 25-6.
The Warriors sealed the bonus point in the 62nd minute when Matawalu tapped a free-kick before stepping outside his man and popping the ball to Seymour who crossed in the corner, though Wight missed his conversion again.
Six minutes later Seymour touched down again, chipping the ball which bounced kindly back into his arms, and this time Wight added the extras for 37-6.
Tim Swinson was sin-binned with nine minutes to go but the Dragons failed to reduce the deficit.
|Glasgow Warriors Score Card|
|Newport Gwent Dragons Score Card|