"The Emergency Operations Centre team, which includes representatives of the border agencies, airlines, ground handlers and New Zealand Police, made their difficult decision only after they exhausted all the viable options available to them."
The airport would conduct a review into the incident and work closely with Aviation Security Service (Avsec) which was conducting its own investigation, Mulitalo said.
Avsec spokesman Mike Richards said Grizz's death had hit staff hard.
"It's a very difficult time for the team. The handlers and the dogs have a very close relationship and it's a very unusual type of work. They're highly trained. They work closely together. They work 24/7. It's a really tight knit group so these things really do have an impact, there's no doubt."
The service would investigate the circumstances surrounding the incident and how it could improve its processes, he told the Weekend Herald.
"That can take a bit of time."
Richards refused to confirm the identity of the handler who had been in charge of Grizz when he got away.
He said the man was "resting" and had just come off a night shift when the incident happened.
"So with that happening it was very stressful because he's got a lot of experience and it's not the result you'd want to have happen."
Meanwhile, people from all over the world have taken to social media to condemn Auckland Airport for the fatal shooting.
The airport's Facebook page has been inundated with angry comments after the incident attracted international media attention.
This puppy-in-training was only on that runway because you asked him to be, the officers training him did not do their job to keep him safe. He was scared and there were other options.
Posted by Christie Black on Friday, 17 March 2017
This is disgusting and so tragic. All because of human greed. I agree with an earlier comment regarding humans causing...
Posted by Kathryn Fowler on Friday, 17 March 2017
How about not having ANY animals working for your airport! Absolutely disgusting!
Posted by Chelsea Warren on Friday, 17 March 2017
Mulitalo said the company understood that people felt strongly about the decision to shoot Grizz.
"We're just going to let people voice their opinions."
The Facebook page also been flooded with nearly 1000 "1 star" reviews, bringing the airport's overall rating down to 2.6 stars out of 5.
Other commenters asked why a tranquiliser wasn't used to sedate Grizz.
Puppy murderers....you people are unbelievable. I guess they don't make tranqulizer darts, animal control officers or...
Posted by Jay Watson on Friday, 17 March 2017
OMG! You couldn't come up with a better way to handle this issue? Like a tranq gun? You had to kill a 10 mo old pup being trained to save people's lives????
Posted by Tish Dougall on Friday, 17 March 2017
Really angry about this, the dog could of been delt like what they do at the zoo, a sleeping dart, not death one. What a...
Posted by Annette Ward on Friday, 17 March 2017
But a top vet told the Herald that getting a dart gun would have been "implausible".
Callum Irvine, head of veterinary services at the New Zealand Veterinary Association, said it was rare for vet clinics to have access to a tranquiliser.
"Dart guns in themselves are very rarely used these days," he said.
"The only place you might find a dart gun would be in a zoo."
Tranquilisers were only accurate at close range, he said.
"It isn't necessarily very easy to sedate an animal that's on the run and in distress like that. In that situation you can actually make the problem worse because the animal becomes partially sedated. It isn't always the perfect solution it might appear to be."
However Irvine "absolutely" understood why people were upset.
"It's a terrible situation," he said.
"But I'm sure the decision wasn't made lightly and fundamentally when it comes to these types of decisions, the most important thing is to protect human wellbeing."