The orphan wasn't even a week old. Its eyes were still closed, its ears still curled, but the tiny black-and-white kitten leaned in eagerly as Samantha Jackson carefully filled a small syringe with formula and offered it up. Immediately, it started to drink from the makeshift bottle, lifting first one paw, then the other, kneading the air, as Jackson gently petted its back.

"Good job, buddy," she said softly.

Its eyes would open soon, Jackson explained. "It's just the cutest thing when they open them and look at you like 'Oh, that's what you look like!' " she said.

Thank goodness for that cuteness, because fostering a neonatal kitten is demanding.

In addition to feedings as frequent as every two hours, around the clock, the fragile kittens must be kept warm (because they can't yet regulate their body temperature) and carefully monitored for illness. They also need to be stimulated with a baby wipe to go potty.

But Jackson, who works full-time from home as a medical coder, doesn't foster just one kitten at a time. That day, she and two fellow rescuers were also caring for 19 more, which had taken over the dining room table and kitchen of her Maple Grove house, giving them a constant rotation of mewling mouths to feed.

That day, she and two fellow rescuers were also caring for 19 more, which had taken over the dining room table and kitchen of her Maple Grove house, giving them a constant rotation of mewling mouths to feed.Jackson is a volunteer with Bitty Kitty Brigade, a new Twin Cities rescue group for the tiniest, most vulnerable orphaned kittens — those up to five weeks old that have become separated from their mothers.

The nonprofit was founded by two Minnesota women this spring to fill a gap in the local animal shelter and rescue community. Since March, it has fostered more than 130 nursing kittens.

"This isn't an easy gig, but it's a pretty great one," said Bitty Kitty Brigade co-founder Mandy Dwyer. "They wouldn't be alive without the work that we do, so it's incredible to be able to witness them growing, thriving, toddling around, snuggling, learning to play and being adopted into loving homes."

Most rescues and shelters aren't equipped to give orphaned kittens the intensive care they need. That's why home foster care is vital.

In many places, such tiny kittens end up being euthanized. That's not the practice at the Animal Humane Society's four metro-area locations, said Mary Tan, the society's public relations manager. But Tan said the Humane Society is thrilled to be able to partner with the brigade instead of scrambling to find someone to take in such vulnerable animals.

"You need special people who can be home with these tiny kittens," said Tan. "And we have bottle-baby fosters, but I tell you, they're difficult to find," said Tan.

The local Humane Society now refers people who find orphaned kittens to Bitty Kitty Brigade and alerts the brigade about kittens at the Humane Society that need intensive care. Local vets, animal control centers and other rescue groups also send kittens to the brigade.

Bitty Kitty Brigade is part of an expanding national network of rescue initiatives that have appeared in the past decade — from the Bottle Baby Nursery Program at Texas' Austin Pets Alive to the Best Friends Kitten Nursery in Salt Lake City.

Fueled in part by heart-melting photos of kitties on social media, in-home, volunteer fostering of neonatal cats is growing rapidly. And kitten crusaders like Hannah Shaw (aka Kitten Lady) have become social media stars. (Her recently released how-to book, "Tiny But Mighty: Kitten Lady's Guide to Saving the Most Vulnerable Felines," also landed on the New York Times bestseller list.)

Caring for the neediest

The dining table in Jackson's spacious house is covered with a row of clear storage bins, cozy fabric-covered heating pads inside. The bins function as warm, safe crates for the tiny animals. (Jackson and her husband eat while sitting on the couch.)

On the floor nearby, she created enclosures for a half-dozen more kittens, which are a few weeks older and getting ready to eat "meatshakes," a combination of formula and kitten food.

She's turned her entire mudroom into a play zone for her little fosters, outfitted with towers, tunnels and even a tiny tepee to hide in. Jackson, who volunteers as Bitty Kitty's medical coordinator, has two dogs but no cats, aside from the steady stream of rescue kittens she fosters until they're adopted.

Not everyone who fosters for Bitty Kitty has so much space to devote to the cause. Brigade co-founder Joan Barrett, a software architect, said she's able to take in several baby felines at one time despite the size of her tiny Minneapolis kitchen — and her four pet cats.

Both Dwyer and Barrett had been volunteering with other rescue groups, and knew how much work it was to foster "bottle baby" kittens before forming the Bitty Kitty Brigade. What they didn't know is that so many other people in the Twin Cities would be up for the challenge.

"For our first year, I kind of assumed we'd do, like, 12 kittens, and it would be the three of us," Dwyer said, indicating herself, Barrett and Jackson.

Instead, they've quickly built a network of more than 60 foster volunteers, whom they train to feed and care for the kittens. They also regularly help people who find kittens to determine if they've been orphaned or if the mama cat is just out hunting. (Keeping kittens with their mother offers the best chance for survival.)

The basic cost for raising a single kitten until they are 12 weeks old is $350. The brigade offsets some of those costs by charging $225 for each adoption. Donations and grants fund the rest.

Some volunteers, like Jackson, take in kittens when they are at their neediest. Others foster older, weaned kittens that don't need as much care.

But Dwyer is still amazed by the number of volunteers who are willing to put in the extra effort required by the smallest of kittens.

"We had so much more interest from bottle feeders than I ever expected, which is awesome," she said.

One perk: Bottle-feeding fosters get to name their foster kittens.

Rescue heartbreak and joy

The women of the Bitty Kitty Brigade say they hope to open and staff a 24-hour kitten nursery, like the one that Shaw, the nationally known "Kitten Lady," runs out of her San Diego home. Shaw regularly shares photos of her tiny wards on her Instagram account, which has garnered nearly 1 million followers.

Dwyer has discovered that sharing photos of impossibly adorable kittens on social media helps drive volunteering, fostering and adoptions for needy animals. A professional photographer, she often snaps glamour shots of the kittens in the brigade's care, posting them to Instagram or Facebook.

Brigade members also share videos about their latest fosters, documenting the difference that time and TLC can make for tiny cats.

Sometimes, though, the stories don't have a happy ending.

In July, Jackson first posted Facebook videos about an orange Manx kitten named Max, which had been very sickly but was recovering. As July turned into August, however, its progress stalled and the kitten worsened and died.

Dwyer said the loss of one of these fragile kittens only strengthens the resolve of brigade members. They take heart that 89% of their tiny charges have beaten the odds and survived.

"We are comforted in knowing that these kittens were given every possible chance. What ultimately carries us through, though, is all the kittens that do make it," Dwyer said. "We're basically growing them from scratch."