Auckland Airport is acknowledging the public outcry after 10-month-old trainee security dog Grizz was shot dead and is promising its own investigation.

Grizz escaped from his handler while being loaded into the back of an Avsex Explosive Detector Dog van on Friday morning. He managed to get through the security area when a gate opened to let a truck through.

The Civil Aviation Authority says it did everything it could to catch Grizz but after three hours, and 16 domestic and international flight interruptions, airport staff directed police to shoot him.

Hundreds of people have taken to the airport's social media pages to criticise the decision, labelling it "despicable, disgraceful and disgusting".

"Disgusted by the choice that was made. A dog that lives to serve its human is murdered because other humans panicked. Surely a tranquilizer (sic) could have been used?!" Carolyne McCourtie said.

"Nice work murdering a frightened puppy to make sure the planes stayed on time. You should be proud of yourselves," Dylan-Beth Clements-Mosley added.

Others have called for the decision-maker to lose their job.

"I hope somebody's head rolls for this," Olwyn Smith said on Facebook.

Auckland Airport is the largest and busiest airport in New Zealand.

On Saturday the Airport released a statement saying it will carry out its own review.

The event was difficult for the whole airport team, particularly for the agencies and staff who tried to do everything they could to capture the dog, the

statement says.

The Emergency Operations Centre team, which includes representatives of the border agencies, airlines, ground handlers and police, made their difficult decision only after they exhausted all the viable options available to them.

"We understand and acknowledge the strong community response to the decision, and our thoughts continue to be first and foremost with the Aviation Security Service dog handler, his colleagues, and all those who were involved in yesterday's events," the Airport said.

Animal rights group have also questioned why a tranquilliser wasn't made available, including SAFE ambassador Hans Kriek who said it would have been a simple solution.

"I suppose they didn't have one (a tranquilliser), but that's not an excuse. They said they were chasing the dog for three hours, surely they could've got one from Auckland Zoo," he said.

"There was a non-lethal solution, they were not prepared. We expect that something is now put in place for future incidents, Mr Kriek said.

But police and Auckland Airport maintain shooting the Bearded Collie-German short haired Pointer cross was the right decision.

Staff found it difficult to locate him as it was dark and he did not have a permanent handler so didn't respond as well as a dog who does.

"We tried everything, food, toys, other dogs, but nothing would work. The area is too vast and too open to try and use mobile fencing," the CAA said.

"All of Auckland's Avsec off duty dog handlers were called in and there was a massive effort to locate and retrieve him."