A Whistler, B.C., sled dog operator accused of slaughtering more than 50 dogs has pleaded guilty to causing unnecessary pain and suffering to animals.

Robert Fawcett, the former manager of Howling Dog Tours, pleaded guilty during an appearance in a North Vancouver court on Thursday, as animal rights activists gathered outside.

Investigators found a mass grave containing 56 dogs near the 2010 Olympic Village in early 2011.

The case came to light when Fawcett submitted a worker’s compensation request claiming he suffered post-traumatic stress disorder following the culling.

The compensation claim details how the dogs were shot or had their throats cut before they were dumped in the mass grave.

Fawcett also describes chasing a dog after it survived being shot in the face, and climbing into the pit of animals to finish killing another animal.

In his claim, Fawcett suggested the dogs were killed because of a slump in tour sales after the Vancouver Winter Olympics, but the companies that employed him denied that.

The slaughter prompted the B.C. government to introduce stricter anti-cruelty standards in the industry. The Sled Dog Code of Practice details acceptable health and nutrition practices for sled dogs as well as proper housing and working conditions, transportation and euthanasia details.

The code emphasizes that culling dogs should not be used for population control, but does not limit the number of dogs mushers can own.

Prosecutors have asked that Fawcett undergo a psychological assessment.

Fawcett now faces up to five years in jail, a $75,000 fine and a lifetime ban on owning animals.

"If it's going to be a slap on the wrist, we are nowhere more forward than we were yesterday," protester Ingrid Katzberg said Thursday.

"It has to be something that is going to tell other people you are going to be punished if you continuously do this to animals."

Fawcett is expected to be sentenced on November 22. Prosecutors did not say what type of sentence they will ask for.

"The position that the Crown takes in this matter will be a principled and fair position that is based on the circumstances of the offence, the seriousness of the offence, but also takes into the account the circumstances of the offender," Crown spokesperson Neil MacKenzie told reporters outside the courthouse.

"It's important to bear in mind the offence is not an unlawful killing of the animals, per se," he said. "It's a killing in a manner that caused unnecessary suffering to the number of the animals that were killed."

Fawcett and his lawyer did not speak to the media.

With files from The Canadian Press and a report from CTV British Columbia