Continuity: The bullies in the park were using a BB rifle but when they're apprehended they were using a much more harmful 22 caliber rifle.
Continuity: In a scene when Fido chases Roy Fraser into a hut, there's a bullet hole on Fido's back. That same bullet hole disappears when Fido's back is visible again in the same scene.
Continuity: In the car washing scene with Fido and Timmy when Helen first brings out the drinks there is a shot with Fido's eye make-up clearly missing. In the next shot the make-up has been reapplied.
Continuity: In the car washing scene with Fido and Timmy, when Helen brings out the three drinks, she closes the door behind her, but the door is open in subsequent shots of the house (we can see the stairwell inside the house).
Factual errors: When Timmy's mother shoots the bully zombie behind the bushes, she fires her gun 9 times, which is not possible since a revolver like that only can fire 5 or 6 bullets before needing to be reloaded.