Faceted Search isn't working on custom 404 page

Issue Summary

Hi,
We've set up are site to use a custom 404 page and when we make a search from this page using the faceted search block, it doesn't work. I don't think it is doing a query.
It works great on the rest of our site.
You can check it at this url: http://www.avenuecalgary.com/dog.
This link will bring you to a 404 page, but both faceted search fields will not work.

Thanks