Apparently a sled-dog touring company called Outdoor Adventures killed about 100 sled dogs after business slowed down and they were forced to cut costs. (link)
Whether or not it was necessary (the company claimed it did all it could to find homes for the dogs), it was apparently done in just about the worst way possible.
The Vancouver, BC Humane Society apparently called for a ban on sled dog businesses, which seems pretty stupid to me. More regulation should be considered, but a ban makes no sense. Working dogs should have the opportunity to work, and that includes sled dogs.