The world is full of zombies and the survivors have barricaded themselves inside a walled city to keep out the living dead. As the wealthy hide out in skyscrapers and chaos rules the streets, the rest of the survivors must find a way to stop the evolving zombies from breaking into the city.
Technically no, no dogs are used, but they do use zombies to the same effect with the same sort of atmosphere and situation, including using live bait.
One of the zombies that attacks Mouse in the later part of the movie is dressed like a clown. It’s a relatively short scene, but one that is sudden. It happens right after Mouse pets the rat.