Ringo the beagle loves all the things every dog would: Running in the yard, rides in the car and the frequent snack.

"He's just so happy to sit right in your lappy," his owner, Amy Bleich, an engineer in Edgewater, Maryland, said.

You'd never know that Ringo, now five years old, had lived the entire first two years of his life inside a small cage at a nearby medical laboratory. When he was first adopted by the Bleich family in 2015, he was nervous around people and other dogs, and thrown off by the feel of grass beneath his paws and cool gusts of wind under his floppy ears.

Dogs like Ringo rarely seem to get a happy ending. A majority of dogs that have been subjects of medical research and experimentation are euthanized and destroyed when the laboratory they live in has completed its tests, according animal welfare groups.

Therapy Dog Ringo with Zev Bleich, age 6. Courtesy Amy Bleich

But, thanks to a growing number of states that have passed legislation cracking down on the practice by mandating that research laboratories must first attempt to adopt out healthy animals that have survived the research tests, thousands more dogs and cats may find homes.

Since 2014, Minnesota, Connecticut, Nevada, California, Illinois and New York have all enacted so-called "Beagle Freedom" laws, named for the dog breed that is most commonly tested on due its particularly docile nature. Just last month, Maryland Republican Gov. Larry Hogan signed his state's bill into law, and on Tuesday, Delaware’s General Assembly passed a similar measure (it had already passed the state Senate), sending it to Gov. John Carney, a Democrat, for his signature.

"Every animal, who can, should be afforded the opportunity at life in a loving home after their time in the laboratory. That’s the very least we should do for them," Kathleen Conlee, vice president of animal research issues for the Humane Society of the United States, told NBC News.

Nearly 61,000 dogs and nearly 19,000 cats lived in medical and scientific research laboratories in 2016, the most recent year for which data is available, according to the Animal and Plant Health Inspection Service division of the U.S. Department of Agriculture. (In total, nearly 821,000 animals were used for medical and scientific testing in 2016, according to the agency’s records.)

Animal welfare advocates don't know exactly how many of those dogs and cats are euthanized after research, but most estimate that a vast majority are put down.

Under the U.S. Animal Welfare Act, medical and scientific laboratories must disclose the number and type of animals on which they’re conducting testing and periodically allow in federal inspectors, who make sure the facilities comply with minimal requirements that pertain to the living conditions of the animals in the labs.

But they aren’t required under the law to report what they do with the animals after the research has concluded, which advocates say is the primary reason states have gotten involved.

A former medical animal test subject, a beagle, hesitates to leave a pet carrier during a First Steps of Freedom Event held by the Rescue + Freedom Project. Courtesy Rescue + Freedom Project

Another five legislatures — in Indiana, Iowa, Massachusetts, Rhode Island, and New Jersey — are currently debating similar bills.

“These are compassionate, common sense bills that don’t have a real down side,” said Matt Rossell, the director of advocacy, programs campaign and public policy at the Rescue + Freedom Project, a Los Angeles-based animal rights nonprofit focused on securing freedom for creatures that have lived in laboratory settings.

“These animals have lived in a very stark environment that does not at all resemble what life looks like for dogs and cats in homes. Small cages, no potty training, they haven't even had opportunities to be outside,” he said. “No fresh air. They haven’t even ever touched the grass.”

Skeptics, many of whom are actually animal welfare advocates, say that the bills are not enforceable, because they don't require institutions to report what they have done with their animals and don’t offer any punitive measures for institutions that don't comply with the requirements that they prioritize adoption over euthanasia.

Volunteers hold a beagle's ear to reveal the tattoo ID from the beagle's time as a medical animal test subject. Courtesy Rescue + Freedom Project

But experts maintain that the laws are working, pointing to public attention and shame as a forceful deterrent.

“I actually think they’re quite effective. These science institutions are large and sophisticated and hyper-aware of public relations and don’t want to be shamed when animal welfare groups expose them for killing all of these animals,” said David Favre, a law professor at Michigan State University’s College of Law, whose expertise is animal law.

“And it's not going to hurt (the institutions) to take the high ground. These (laws) don’t curb their research, they just help the dogs,” said Favre. “And besides,” he added, “you don’t really want to go and arrest scientists anyway.”

Advocates, and pet owners, say the benefits of the bills don’t just apply to animals.

Jeremy Bernard, a southern California author who worked as former President Barack Obama’s social secretary, says his life has only been enriched by the two beagles — both former inhabitants of medical labs — he’s adopted in recent years.

Jeremy Bernard and Mason Courtesy of Jeremy Bernard

Mason, adopted in December, came to him a "nervous puppy" who got especially anxious before his breakfast, Bernard said.

"I got the sense he must have been fed and tested in the AM," Bernard said.

But now, just six months later, “he loves playing with other dogs and people … and his breakfast.”

“He’s so affectionate,” Bernard said. “I watch him when it’s windy and he looks up at the sky and I don’t think he has any idea what wind is. But it makes him really happy. And it makes me happy watching him.”

“I don’t think he has any idea what his life used to be like,” he added.