According to the BBC, the rescue is thought to be one of the biggest ever dog rescue efforts in the US.
President and chief executive of the U.S. Humane Society Kitty Block revealed that the massive rescue effort is not an overnight job.
"It’s going to take 60 days to get all of these animals out, and working with our shelter and rescue partners across the country, working with them to get these dogs into eventually into ever-loving homes," she told Reuters.
Shelters across America have begun receiving the beagles, who will receive veterinary exams, vaccinations, and other treatments before becoming available for adoption by the public.
The mammoth rescue and rehoming effort comes after the U.S. Department of Justice sued pharmaceutical research company Envigo RMS LLC over alleged breaches to the Animal Welfare Act violations at the Cumberland facility.
Envigo's parent company Inotiv Inc announced in June that the facility would be closed as a result.
The company settled with the government the following month and paid no fines for their alleged breaches to the Animal Welfare Act.
According to a statement released by the U.S Human Society, government inspectors found beagles were being killed instead of receiving care for easily treated conditions.
Nursing mother beagles were denied food and the food they received contained maggots, mould and faeces.
They also found that 25 puppies died from cold exposure over an eight-week period.
Some dogs were injured when attacked by other beagles due to living in overcrowded conditions, the statement added.
Republican state Senator for Virginia, Bill Stanley, revealed that he had attempted to trigger the mass beagle rescue three years ago.
"I tried to shut them down in 2019, but was not successful," he told Reuters. "But over the years, we never stopped fighting."
Now it is up to the U.S Humane Society to find shelters that can make space and find homes for the 4,000 or so dogs.
"Finding partners who can make space ... in the summer - a time of year when animal shelters already are over-capacity - will be a feat of epic proportions," they said in a statement.
"We are ready to take on the challenge and are grateful to our rescue and shelter partners... whose dedicated efforts will make it possible for these dogs to find loving homes."
Featured Image Credit: The Humane Society of the United States/Facebook.