My 5pm flight was canceled at the last minute. I was rebooked for a non direct flight leaving at 7pm. Because it would be too long for my dog to be in a crate, I got in the long understaffed line to change my flight. I assumed my dog was waiting to be put on the next flight. I was in line for 1.5 hours. There was only one agent. They opened up another line and then closed it shortly after and the agent that was helping left. The two agents that were then helping people left everyone to help with an incoming flight and left everyone standing there. Not acceptable. When I finally got my flight changed, I asked where I would get my dog. The agent informed me, my dog had been sent down to the oversize baggage!!! When I got to the oversize bag, a couple informed me that they had taken her off the carousel 30 minutes prior. She had likely been there for at least an hour!!! So not only did WestJet send my dog out to oversize without informing me. They did not even have an agent take her off the carousel, so other bags could just continually bang into her crate and she was left unattended for an hour!