Could the "zombies" be people infused with some sort of essence of dog?
  • Dogs and Zombies both have an extremely good sense of smell.
  • Zombie attack sounds are remarkably similar to dog snarls. For an example see Episode 3 - The New Arrivals - Part 1 of 3 (17:39).
  • Zombies come in different varieties, much like dog breeds (greyhounds~runners, mastiffs~behemoths, chihuahuas~creepy little ones).
  • Certain zombies ("howlers") call out to communicate over great distances similar to what wolves do when they howl.
  • Zombies have been seen traveling in cliques or packs. Even in the first episode, Michael describes the attack on the honking car as being "like a pack of wild dogs".
  • When reviewing the video of the sweat bottle experiment, Riley says that they were drooling like her dog did before he was neutered.
  • Skittles described a behemoth chasing a cat up a dump truck. Dogs are known to chase cats.
  • Dogs stereotypically do not like baths and Tommy was getting very belligerent about washing himself off just as he was starting to turn.
  • At the beach house, Michael found a zombie that was rummaging in the pantry, eating dog food.
  • Dogs are the only species of animal that we are told are immune to being turned. This might be because a dog infused with the essence of dog would still be a dog.
  • Tanya says they seem to exhibit more animal traits than human.
  • At the hospital, Kalani comments on the hair and nail clippings and says that it looks like someone was trimming a Great Dane.
  • The One With The Markings appears to epitomize the alpha-dog role, with other zombies taking orders/direction from him.

With all of the comparisons and similarities to dogs, it is definitely something to ponder.