Megan Lemaire always wanted a dog growing up, but was never allowed to have one.

So when Lemaire, a 22-year-old student at Washington University in St. Louis, heard that area shelters needed foster families to care for animals during the coronavirus outbreak, she and her roommate applied to provide a home to a pet in need.

They drove to the shelter, where they were paired with the second dog they met — Vorhees, a pitbull mix. "We just really loved her," Lemaire said.

As coronavirus spreads across the U.S., Americans in some of the country's hardest-hit regions have stepped up to foster and adopt animals, keeping them out of shelters. NBC News contacted shelters and animal advocacy organizations with facilities in California, Michigan, New Jersey, Connecticut, New York, Texas, Washington, Florida, Georgia, Illinois, and North Carolina. Every single organization said it was overwhelmed by the outpouring of community support that got animals out of shelters and into loving foster and adoptive homes.

Megan Lemaire takes her foster dog, Vorhees, on a walk in St. Louis. Vorhees has lived with Megan and her roommate for three weeks. Arno Goetz

Humane Society of the United States President and CEO Kitty Block said that the organization has worked with its 400 shelter partners to spread the word about the need to clear shelters by placing pets with foster and adoptive homes. "The call has been answered," Block said.

Matt Bershadker, president and CEO of the American Society for the Prevention of Cruelty to Animals (ASPCA), said that the organization has seen a 70 percent increase in animals entering foster care in their New York City and Los Angeles programs compared to this time last year.

In Los Angeles, Bershadker said the organization is delivering kittens to foster and adoptive families using ride-sharing apps. A spokesperson for Los Angeles County Animal Services told NBC News in an email that the county placed 307 animals in foster care and found homes for 919 pets in March.

Victoria Gingrey, a spokesperson for The Humane Society for Tacoma and Pierce County in hard-hit Washington state, told NBC News that the shelter has placed 475 animals in adoptive homes since March 1. The shelter had only 25 animals available for adoption as of Wednesday, which Gingrey said is "pretty low" for this time of year.

The Liberty Humane Society shelter in Jersey City, New Jersey, across the Hudson River from the pandemic's epicenter in New York City, put out a plea to the public to foster pets, but Executive Director Irene Borngraeber said she did not know whether people would step up to care for the animals.

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Borngraeber said the shelter was "overwhelmed" by the level of response they received from the public. "We were actually able to place every single one of our animals into foster care, the day before [New Jersey's] shelter-in-place order formally went into place," she said.

Baytown Texas Adoption Center was able to clear out its shelter by March 28. The shelter, just 30 minutes outside of Houston, had no foster program in place when the state announced its first coronavirus case on March 4. But April Moore, the animal services manager for the city, said that the shelter began building a foster program on March 16. Just eight days later, the shelter placed its first dog in a foster home. The shelter had just one dog left in its care when NBC News spoke to Moore on Wednesday.

In Georgia, shelters have also found success placing animals in adoptive and foster homes. "We've seen an incredible outpouring of support," Atlanta Humane Society Spokesperson Christina Hill, said. "It's been really heartwarming to see that."

Hill told NBC News that the shelter has placed 217 animals in foster homes since March 11, and found 151 animals permanent homes between March 11 and 15. As of Tuesday, Atlanta Humane Society had only 15 animals in the shelter.

And between April 5 and April 12, Chicago Animal Care and Control had no adoptable animals, according to an emailed statement from spokesperson Jennifer Schlueter.

Now for the bad news

The shelters are empty now, but experts worry about the future.

Shelter directors told NBC News they worry that the economic impact of the pandemic, which hit the U.S. at the start of peak breeding season, may cause an influx of homeless pets in the coming months.

Early spring marks the beginning of "kitten season," when animals tend to reproduce in large numbers. Usually, shelters work with animal control officers to trap and sterilize homeless animals to combat overpopulation. And new adoptions are spayed or neutered before the adoption process is completed.

But most of the shelters NBC News contacted have halted spay and neutering procedures, saving surgical veterinary care and essential supplies for the sickest animals. The Humane Society of Greater Miami is spaying and neutering shelter animals once per week, but the clinic is closed to the general public.

Susie, a dog fostered and adopted during the coronavirus pandemic, plays with her new owner. Courtesy Atlanta Humane Society

With an estimated 22 million Americans now unemployed, the shelter directors said that they worry it will be difficult to find homes for the surge in newborn animals they expect to see, and that already-adopted pets may be surrendered by families that can no longer afford to care for them.

The majority of shelters NBC News spoke to have programs to get pet food to families in need. Other shelters, like the Humane Society of Greater Miami, do not have a pet food bank but provide the food and supplies foster families need to care for their pets.

Bershadker said that the ASPCA has provided 9,000 pets with food at its distribution centers in New York City, Miami, Fla., Asheville, N.C., and Los Angeles. He said the organization expects to serve 100,000 pets by mid June.

"The idea behind this is to provide the critical resources to pet owners so that they can responsibly keep and care for the pets that they love and they're bonded to — keep them out of the shelter in the first place," Bershadker said.

And with at least 720,000 coronavirus cases in the U.S. as of Saturday, shelters are concerned they may see an influx of animals surrendered or abandoned by sick owners.

Scott Giacoppo, president of the National Animal Care and Control Association, told NBC News that the best way to prevent that type of overcrowding is to make a plan for what will happen to a pet if the owner becomes sick with COVID-19. He said that owners should put a list of multiple people who would take their pet in on their front door, along with contact information and care instructions, in case animal control is called for an unresponsive pet owner.

Ziggy plays with his new owner and two of his foster kitten housemates. He was fostered and adopted during the coronavirus pandemic. Courtesy Atlanta Humane Society

If foster families are no longer able to care for their animals, the shelters NBC News spoke to said they either recruit a new family to take the animal or take the animal in while they try to find the animal a new home. "While we always want to empower our foster care providers to take an active role in helping the pet in their care find their new home," said Moore. "We are also prepared to take a pet back into care at the shelter when or if the need arises."

Hill said that more than 70 percent of the animals in Atlanta Humane Society's foster care program have already been adopted. But she emphasized that it is important for foster families to try to let the shelter know as soon as possible if they can no longer care for the pet, so that the shelter can find another home.

Shelters are also in need of more financial and material donations to help provide essential care for their animals. But James Bias, executive director of the Connecticut Humane Society, said that it is important to find out what a local shelter needs before trying to donate. "Reach out. Check their website, check their social media," Bias said. "Don't assume that they're going to need certain things and just show up with those items."

In St. Louis, Lemaire has now had Vorhees at home for three weeks. In addition to the comfort of daily dog snuggles, Lemaire said having a dog has provided a lot of structure to a schedule that would have otherwise revolved around remote classes. Lemaire said she does not plan to adopt Vorhees because of the uncertainty of post-graduate life, and has worked with the organization she fosters for, the Center for Animal Rescue and Enrichment STL, to place the dog in a permanent home. Lemaire said that the experience has been "a true dream come true."