It comes after two deaths during race days in Christchurch in recent weeks.
Since the racing season began in August, animal organisation SAFE said there have been 5051 injuries, 65 fractures and six deaths.
However, the industry said this was well down on prior years due to it implementing an Injury Reduction Strategy.
Head of investigations for SAFE Will Appelbe told Checkpoint the recent deaths were "horrific".
One of the dogs was 4 years old and suffered two broken legs while racing and had to be euthanised.
The other dog was just 2 and had to be euthanised after suffering from an open fracture, he said.
Appelbe said they were just two within a wider context, which showed dogs experienced "extreme suffering" in the racing industry.
“The dogs do continue to suffer, do experience an extreme lot of suffering and it’s been allowed to continue for far too long. In the last racing season, 40 percent of greyhounds that raced suffered an injury ... that’s a feature of an industry that multiple reviews have said is inherently dangerous.”
Appelbe said it had been an issue for far too long and three reviews had been published since 2013, all identifying "significant animal welfare concerns" that continued to persist.
While campaigning for the election in 2023, now Prime Minister Christopher Luxon said greyhound racing should be banned.
But it was not good enough that no timeline had been put on an action that was the only way to protect the greyhounds, Appelbe said.
The previous Labour government should have moved to ban it sooner, but there was an opportunity for Luxon to put his words into action and "protect these greyhounds from further harm".
Dogs were suffering and it was not good enough, Appelbe said.
In a statement to Checkpoint, Greyhound Racing New Zealand said that it was saddened and disappointed by the euthanasia of the two greyhounds.
It said euthanasia was considered by an independent veterinarian to be the most humane option.
It said the rate of race day euthanasia had reduced drastically, going from 67 in the 2018/19 racing season to seven in each of the past two seasons.
Greyhound Racing New Zealand said this was due to animal welfare measures it had recently put in place .
