In the current version of the BO3 Modtools (Beta), dog spawners are missing from the test map but are not disabled in the scripts by default. This causes you to get stuck on an infinite dog round when you play your map. You can fix this by adding dog spawners or disabling dogs in your map file. Treyarch also did not include a dog spawner prefab with the tools at this time, so you would normally have to grab stuff from The Giant mapfile.

If you want to add dog spawners to your map or disable them, check out the wiki page: https://confluence.ugx-mods.com/display/UGXMODS/BO3+%7C+Adding+Dog+Spawners+or+Disabling+Dog+Rounds