With just two rotations available from half time, the Cats made it six straight wins over the Dogs with a 15.17 (107) to 13.8.(86) result.
They first lost Jared Rivers to a right knee injury in the first quarter, and were forced to make their substitution at the first change.
Adding to the interchange pressure, Josh Caddy copped a head knock from Brett Goodes in the second quarter, and was forced out of the game.
The incident is likely to be looked at by the Match Review Panel.
"It (the injuries) makes it a little more difficult, but I don't think that was the main reason that we played poorly in that last quarter," Cats coach Chris Scott said.
"But to hang on and win the game is a positive and we did what we needed to do. We'd prefer that we play a little bit better.
"I'm probably asking for a little too much to expect 100 per cent output, I certainly expect 100 per cent effort, but the reality is we're 5-0 and we've come through a pretty tough first five weeks in pretty good shape."
The Western Bulldogs launched a last-ditch attack in the fourth term, with three quick goals, to reduce the margin from 37 points to 19.
With a full interchange bench at their disposal, the Dogs came home with fresh legs.
Liam Jones had a chance to reel the Cats in even further when he ran into an open goal, but crucially, his kick was off-target.
Adam Cooney fought desperately for his side, showing the aggression that was the trademark of his Brownlow Medal-winning season.
The Bulldogs held Geelong goalless in the last, but couldn't do enough to make up the margin.
"Late when the door was still ajar, and I don't know whether we could have got there or not, but you never die wondering, we needed to work a bit harder to get the ball back," Bulldogs coach Brendan McCartney said.
"We're really confident about what we're teaching our players, in particular our younger players, who have a lot to learn."
The Cats were dynamic in the midfield, thanks to the pace of Steven Motlop, while Harry Taylor continued his successful foray up forward to finish with five goals.
Joel Selwood led from the front once again, overcoming a blow to the stomach in the third quarter to register 21 disposals and two goals.
For the Western Bulldogs, Liam Jones started the game with intent, taking four first half contested marks and kicking three goals. He finished the game with four.
Five talking points: Bulldogs v Cats
"He's on his way. He's the classic work-in-progress young forward," McCartney said.
Second-gamer Jake Stringer made the most of his chances in the forward 50, with three goals to his name.
Will Minson continued his dominance in the ruck, with 37 hit-outs beating Geelong's combined total of 25.
?"Will's been around a fair while, and he's just entering that age where ruckmen do their best work," McCartney said.
The Bulldogs had most of the play in the second quarter, but late goals to Geelong saw the Cats take a 30 point lead into half time.
Selwood was awarded one of those goals with a soccer kick, but the replay cast doubt about whether his foot actually made contact with the ball.
Even so, the video review system was not employed, and the goal stood.
"A lot of things happen pretty fast on the goal-line. I don't envy goal umpires sometimes," McCartney said.
Tom Hawkins was a late withdrawal from the match with back tightness, replaced in the selected side by Cameron Guthrie.
He is expected to be available next week.
WESTERN BULLDOGS 3.1 6.3 10.6 13.8 (86)
GEELONG 5.5 10.9 15.12 15.17 (107)
GOALS
Western Bulldogs: Jones 4, Stringer 3, Smith 2, Cooney 2, Dahlhaus, Roughead
Geelong: Taylor 5, Motlop 3, Selwood 2, Podsiadly, Smedts, Johnson, Kelly, Christensen
BEST
Western Bulldogs: Boyd, Jones, Picken, Minson, Cooney, Liberatore
Geelong: Johnson, Taylor, Kelly, Enright, Selwood, Motlop, Bartel
INJURIES
Western Bulldogs: Nil
Geelong: Rivers (knee), Caddy (head)
SUBSTITUTES
Western Bulldogs: Jackson Macrae replaced Patrick Veszpremi in the third quarter
Geelong: Taylor Hunt replaced Jared Rivers at quarter-time
Reports: Nil
Umpires: Hay, Findlay, Fisher
Official crowd: 26,153 at Etihad Stadium
