British Columbia SPCA officers headed to Whistler Monday to investigate claims that 100 healthy sled dogs owned by a tourism operator were slaughtered.

The allegations are contained in a filing to WorkSafeBC, the provincial workers' compensation board.  

According to a release from Outdoor Adventures Whistler, an employee of a company called Howling Dogs was compensated for post-traumatic stress after shooting 100 dogs in April 2010.

Outdoor Adventures Whistler acknowledges it had a financial stake in Howling Dogs at the time of the cull, but didn't take operational control of the company until May 2010. 

The release says: "OAW was aware of the relocation and euthanization of dogs at Howling Dogs in April 2010, but it was our expectation that it was done in a proper, legal and humane manner."

The man who was compensated hasn't been identified. Outdoor Adventures Whistler said he is no longer managing Howling Dogs. A new manager has been hired.

His lawyer, Corey Steinberg, said the man made every effort to find adoptive homes for the dogs. Steinberg told CBC News that when he wasn't successful, a group, including executives and the man, agreed euthanasia was the only choice for the sickest and oldest dogs in the pack.

"He just wanted the greatest happiness for the greatest number of dogs. He had to choose — 'Do I keep 200 dogs and make their lives great, or do I stick here with the 300 that I have?' And I'm being told by my employer, 'You deal with it, you figure it out, there's not really much more we can do for you,'" Steinberg said.

The general manager of cruelty investigations for the provincial SPCA, Marcie Moriarty, wonders why the company had so many dogs when it couldn't keep them healthy. She said the dogs appear to have died a horrible death.

"I won't use the term euthanized, [which] implies a humane death, and I can say that based on his description, at least a number of dogs did not have a humane death. His descriptions of using a shotgun, blowing off half of the dog's head while it ran off, a dog crawling out of a mass grave, it just made me shudder," Moriarty said.

Moriarty said investigators would try to locate the burial site and perform necropsies.

Outdoors Adventures Whistler told CBC News the incident is tragic and regrettable, and a new policy has been put in place to ensure all dogs are euthanized at a veterinarian's office.

The company also said it has implemented a neutering program for all male dogs to mitigate unwanted pregnancies in the pack.