"You'd also need to consider exactly how these creatures would act compared to the normal zombies. Resident Evil showed humans as the stereotypical stumbling corpses, but infected dogs and crows remained just as agile as in life. How does that even make sense?

Imagine an infected bird that doesn't have the coordination to get off the ground, or a slow-moving chihuahua that takes a full minute to cross the street because it can barely walk without falling over."