July 20, 2010 -- It's become a strange staple of the local news cycle. Men and women, young and old, with an addiction unlike any other.
They are people with an overwhelming need to collect, and even control, animals.
"I won't let them go outside and run and get hit by a car or maybe find something and get poisoned," said animal lover Bonnie, who requested that her last name not be used. "No. And if that's cruel, I am guilty."
"I look at it and I think how did it get this way?" said Don, a cat lover who asked to be identified by his first name. "How did I let it get this way?"
Watch the full story tonight on "Nightline" at 11:35 p.m. ET
Watch "Confessions: Animal Hoarding" premiering on Animal Planet Wednesday, July 21 at 9 p.m. ET
The difference with animal hoarding is that this drug can love you back.
"They mean more to me than any human could," said Bonnie. "People stab you in the back, an animal won't."
At one time Bonnie had more than a hundred pets. Animal control took them all away -- and she immediately began acquiring more.
"I don't like to go shopping, unless it's a pet store," Bonnie said. "When I go into a pet store, it's like, I'm home. I don't care if I don't have a morsel to eat, my dogs will eat."
Hoarders Start Small
In any given year, thousands of Americans hoard more than a quarter of a million animals.
Animal lovers like Don. What started as a few cats for him soon became more than 30.
"One day you look down and you've got 30 pairs of eyes looking at you going, 'Are you goin to feed me?'" Don said.
He overcame an addiction to methamphetamines and has seemingly replaced one habit with another.
"The hardest thing to do is ask for help, because then you are saying whatever's happened in my life I'm out of control of, I can't deal with it on my own," he said.
His wife, just out of the hospital because of kidney disease, is at elevated risk of infection. Because of the kitty mess, she hasn't been home for six months.
"Junk. Everywhere," Don noted. "'Cause we just can't seem to clean it up. That's cat urine on the bottom of the refrigerator. That's the stove. There's cat urine on the wall. On our washer."
But among animal hoarders, it's Janice who takes the prize, with 97 dogs and 15 cats crowded into her tiny trailer.
Like Don, her relationship with her animals is threatening her marriage.
Animal Hoarders: 'My Dogs Are Like My Kids'
"I don't think you'd want to sleep with 20 dogs, 30 dogs and on a daily basis," said Janice's husband, who also is named Don. "And it just, you know, [I'm] tired of it. I slept in that camper to be able to get sleep."
Janice, who lives in Virginia, began breeding Yorkshire terriers, but she eventually added more breeds and stopped selling the puppies. She lived that way for 12 years.
"My dogs are like my kids," she said. "They're all sweet dogs. They're just incredible."
Caring for her "kids" is a full-time, exhausting job.
"It's constantly all day long that I have to just keep going behind them and, you know, and filling the water back up, picking the paper back up, you know putting new paper down," she said.
Still, the trailer is never clean or quiet.
"The dogs are really loud," said Lindsay, Janice's daughter. "They're all barking at once. The smell is pretty horrible."Janice has not seen her grandchildren in months.
"I mean as much as I love my grandkids, and believe me that's a lot, but I also love my dogs too," Janice said. "You know you've seen these guys grow up from puppies, you know, and you've taken care of them."
Lindsay eventually called on Dr. Karen Cassidy, owner and clinical director of the Anxiety and Agoraphobia Treatment Center in Chicago, to set up an intervention. The goal? Convince Janice to give up all but two dogs and one cat.
Animal Hoarder Intervention
During the intervention, Janice said: "Seriously, I don't think I can pare down to two dogs and one cat, because yeah, I've spent so much time with them and there's certain ones that I'm like really, really super close to."
Lindsay responded: "But see that's, that's where it gets me, because you spend more time with the dogs than you do with your daughter and your grandkids. And don't you think that's more important?"
"Well yes, it is more important," said Janice.
"But you're picking the dogs," said Lindsay.
"You know, honestly speaking, if you were looking for a home for an animal -- so let's say you were running a pet shelter. Would you pick your place?" said Cassidy.
Janice began to cry.
"Mama, we're going to be all right," said Lindsay.
Animal Hoarders: 'Unconditional Love'
It's a painful process. Humane society volunteers filled an entire tractor trailer with animals as Janice learned to let go.
"I felt like it was pulling on my heart cause I wanted to give them one more hug goodbye," she said after the animals had gone. It had been almost four months, but that moment was still tough to think about.
"I felt good for the dogs -- I knew I did what I had to do, but it was hard because I loved them," Janice said.
Janice has moved into her daughter's home with just one cat and two dogs.
She's getting a divorce and says her life is better, but she still misses those dogs.
"When you think about it a dog will love you no matter what, and when you look at it, they say, dog spelled backwards is God, and He gives you unconditional love, and so do they," Janice said.
Janice said she didn't think the term "animal hoarder" applied to her.
"I don't think that applies to me, because it wasn't something I chose to do," she said. "It wasn't something that I just went out and got that many dogs because I decided I wanted to start gathering all these things, you know? It wasn't like that. Mine just snowballed. ... I didn't go out and initially buy 100 dogs."
Don, meanwhile, faced possible jail time for abuse charges. He finally surrendered to animal control. Workers found dangerously high levels of ammonia from all the urine and several gruesome surprises -- including dead cats.
After a cleaning and new carpets, Don was reunited with his wife, Linda.
But not all cases are so cut-and-dry. Bonnie refused to give up any animals, though she did install a doggie door so the animals could go to the bathroom outside.
Janice said she gets the same amount of love from each one of her pets.
"The love I get from them, [it's] unconditional," Janice said. "It's definitely unconditional love, because they love you no matter what. They're there. I talk to 'em, you know. It sounds funny as it is, but I talk to 'em. And they know. They know I would do anything for 'em."
Janice said she missed the pets she gave away, however.
"I always miss the others," she said. "I'll always miss 'em."