As a dog allegedly mauled his colleague, Detective Sergeant Ivan Naspe feared the pitbull would go for the female constable's throat.
He said he knew he had to act fast and discharged his Taser twice.
"That had no effect on the dog, so I used my Glock and eventually stopped the animal," he said.
"Luckily for us, only body parts below the throat line were attacked."
Detective Sergeant Naspe's actions during the July 1 incident in Rivett were lauded on Tuesday morning when he received an award recognising his bravery.
The pitbull's owner, Matthew John Millard, has pleaded not guilty to several charges and remains before the courts.
Detective Sergeant Naspe said his injured colleague was recovering well, and that the outcome could have been much worse.
"Any day where you draw your firearm as a police officer is quite nerve-racking," he said.
"It’s an absolute honour [to receive recognition]."
Detective Sergeant Naspe was among more than 60 officers to receive honours at the ACT chief police officer's awards on Tuesday morning.
A civilian, Stephen Oliver, was also commended for coming to the aid of the injured officer during the alleged dog attack.
Detective Sergeant Michael Laverty, who helped solve the 2004 shooting of security guard Kevin Matangi outside the Mawson Club, was also recognised for his service.
He took on the case in 2009 and spent nearly a decade working on the complex investigation, which wrapped up when David Allen Will, who masterminded the crime, was jailed earlier this year.
Mark Anthony Munro and Sam John Melkie had previously been locked up for their roles in the daylight robbery, in which a Chubb armoured van was targeted outside the southside club.
Detective Sergeant Laverty said he walked away from a meeting with Mr Matangi determined to get a result for him.
"It was very pleasing when I got to ring the victims and inform them that we had made arrests and that we had instigated a prosecution," he said.
"The relief from those people was fantastic. It’s a feeling you just can’t describe until you’ve experienced it yourself.
"I don’t see [policing] as a job. It’s an adventure that I come to every day, and every day’s a little bit different to the next."
ACT chief police officer Justine Saunders praised each of the officers who received honours on Tuesday.
"Police put themselves on the line every day for the ACT community," she said.
"Today is an opportunity to recognise their commitment, their perseverance, their resilience and professionalism every day."