I started a zombie outbreak?

Zombie Zoo

The abyss is an easy place to go insane. It is important that I keep my thoughts straight. Going over what I've discovered so far is the easiest way to keep myself occupied during my stay here.
First of all, zombies are real.
You can become a zombie by being bitten or scratched (only if blood is drawn.)
The location of the bite of scratch determines how long it takes to turn.
A bite to the knee or down typically takes anywhere from 8-15 hours, side effects can be depression and uncontrollable bouts of anger.
A bite to the upper leg can take about 5-10 hours before turning and can cause major disorientation.
If bitten on the arm you have approximately 4-10 hours before turning, this can cause you to become violently ill and even lose consciousness.
A bite to the head or neck area will cause you to turn instantly.
If a zombie attacks you and you are bitten you will turn unless your brain is devoured entirely. (The homeless man devoured whole, for example)
Zombies tend to travel in packs of two or more, gathering together for larger opponents and major food sources.
Without a head a zombie can not survive, yet they can lose every limb, half of their body, even most of their face.
Zombies get smarter and stronger the longer they are alive? Undead?
Zombies tend to keep some of their prior living self: athletes are faster, nerds are smarter, trained soldiers can fire a weapon (though not completely accurately.)
Zombies must rest at least twice in a week or after being badly injured.
If you die but are not infected you will stay dead.
Animals can become zombies, but not all animals: flying creatures such as birds and insects seem to be immune.
Zombies are actually pretty smart, they eventually relearn survival skills that they had been taught when they were alive, like marking a trail, tracking down food, climbing, running, working together, mending broken or injured parts (although they will not heal because the flesh is dead.)

I don't know enough about their DNA though, I don't know the basics of what makes them want to devour fresh human meat, I don't know what makes them the way they are. I don't know how all of this actually started, or where that dog even came from, I don't know if it's even possible to create a cure. There is too much that I don't know. I don't know why I keep coming back to the abyss, or how.

But most importantly I need to know where that dog came from.

The smell of rotting flesh fills my nose. Cold metal bars surround me. What once was a zoo caging poor animals for human pleasure now held hundreds of zombies. Each in their own individual prison, trapped behind bars. Undead Chloe stumbled around to each of the four walls growing more irritated with each trip around the never ending cycle. Men were shouting in the distance, their voices slowly growing louder, but it wasn't the horrified screams I'd grown so used to. They were laughing, joking with one another. They walked up over the hill carrying a bucket, they made stops at each individual cage and tossed in a lump of bloody raw meat. The zombies immediately jumped onto the food and began eating, like animals. They grew closer.
"This our new gal?"
"Yea, she's feisty, careful when you feed her."
"From those kids? How'd they manage that one, I heard we lost two men just getting her into the cage."
"No clue but as long as they continue to supply the entertainment I'm not gonna question it."
The men stepped up to the cage, eyes locked on the zombie. Chloe flung her arms between the bars the smaller of the two men flinched but lucky for them they were just out of reach.
"Which one is she anyway?"
"Number 126."
"So we have two new ones?"
"Yea, that's $500 each, the lab will pay top dollar for this one though, she is smarter than the rest. Watch."
He tossed in the nasty chunk of bloody meat, Chloe paid it no mind, she was not interested in what they had to offer.
"She won't eat the cow meat, she's only after us." He laughed.
"They'll be around tomorrow to pick which they want, but tonight" he chuckled, a smirk plastered across his face.
"We party."

Hours ticked by, Chloe did not eat, eventually she stopped moving as well. Although I was not restricted by the bars I couldn't leave her side without risking getting sucked back into the abyss. I had never known the feeling of being trapped. I'd never been to prison but this had to be quite similar. At this point I debated which was worse: the abyss or a small metal cage meant to hold animals.

Do prisoners feel like this, trapped, caged in, afraid? There's nothing to do but pace back and forth. Back and forth. Back and forth. Waiting for something to happen, something to change. Staring down the same four walls, the same surroundings. Moans and groans from fellow prisoners ringing in your ear like a symphony of dread. The only difference I can think of is watching your body slowly become hungrier.

Night had fallen, after what felt like years but could have only been hours, the men from earlier returned with a couple friends. Each carried a pack of beer and some wood.
"Right here guys. Next to the new gal, I think you'll like her."
They set up camp, pulling chairs out of nearby bushes and starting up a fire to sit around. They drank and laughed and drank some more. It's obvious this isn't the first time they'd done this kind of thing. The man who had tossed the food into the cages at dawn had traded his bucket for an animal restraining pole. It didn't take long for them to get completely wasted and start nagging at nearby zombies.
One stumbled up to Chloe's cage,
"Hey, hold my beer!" He shouted tossing his can to the nearest person as he sauntered up the the metal bars. Chloe waited patiently just out of reach. He lost his balance and fell face first into the bars, zombie Chloe lunged forward grabbing whatever she could to hold on to him. Thrusting her face against the bars barring rotted teeth and screeching. Nearby zombies perked up at the wails coming from the drunken man. They rushed their cages, bouncing themselves off of the bars, howling into the night.
"Shit! Dan! What the fuck man!"
Another man tried grabbing onto him to pull him away but Chloe wouldn't budge.
"Shit! Mark! Get the pole! Get her off of him!"
Protest rang out as mark grabbed the pole with shaky hands, fumbled for the keys to the cage, and approached from behind Chloe.
"She's too far away I'll have to open the gate" he muttered to himself as he turned the key in the lock. Chloe dropped the crying man and spun on her heel, within seconds she slung herself against the door sending Mark tumbling to his ass.
"She's out! She's out! Lets go! Mark, man run!"
They scattered, leaving Mark lying on the ground.