(CNN) -- An employee of Canada's Outdoor Adventures company admitted to slaughtering 100 sled dogs, according to a workers compensation report he later filed.
The employee -- whose name authorities have not yet released -- worked as a general manager of Howling Dogs tour company in Whistler, British Columbia. He claimed he was suffering from post-traumatic stress after carrying out company orders to kill the dogs, the report said.
A company with a similar name, Howling Dogs Tours, in Canmore, Alberta, has no connection with this case.
The man cited "a slow winter season" that compelled him to decrease the size of the company's dog pack by 30 percent, the report said.
The slaughter took place over the course of two days in April 2010, when he allegedly shot and knifed the animals before dumping them into a mass grave, including at least one dog that was later found alive, the report said.
The man said he was "given a job to finish and did not want to prolong the suffering and anxiety of the whole kennel population," according to the report.
He claimed he wanted to "stop the nightmare" after firing multiple gun shots at the dogs' faces and throats, inflicting mortal wounds as they fled for safety.
British Columbia's Society for the Prevention of Cruelty to Animals said it is investigating the incident with the provincial workers' compensation board.
Whistler Police Sergeant Steve LeClair told CNN Tuesday that he is investigating the incident and that the man has not been charged with anything at this point.
Outdoor Adventures Whistler, which currently owns the company but says it didn't take operational control until a month after the incident, issued a statement saying it was aware of the "relocation and euthanization" of the animals but was "completely unaware of the details of the incident."
Graham Aldcroft, spokesman for the company, said in the statement that there are no longer firearms on the site, and in the future, sled dogs will be euthanized in a veterinarian's office.
The man claims he had the "approval of a veterinarian" to shoot the dogs prior to the April killings, after attempts to have the dogs adopted were met with only limited success.
Outdoor Adventures was still advertising dog-sled tours on its website Tuesday, saying that its "lengthened tour means more time with the puppies."