Suzanne D'Alonzo from the Animal Welfare League of Alexandria, Va., helps unload seized puppies and dogs at the Fairfax County, Va., Animal Shelter. Animal lovers along the East Coast responded after authorities seized 1,000 dogs from an alleged puppy mill in southern Virginia.

Washington ? Some of the adult dogs arriving at the Montgomery County, Md., animal shelter Thursday acted like newborn pups with splayed legs, wobbly as they tried to walk. They had never been on solid ground.

At first, they didn’t know how to eat from a bowl, so accustomed were they to the troughs at the puppy mill in southwestern Virginia from which they had just been rescued. Several had matted hair around their eyes and couldn’t see. The pads of their feet were sore or cut from being confined to wire cages.

When word of the dogs’ plight surfaced last week on the Web site of the Humane Society of the United States – that officials in Carroll County, Va., had seized nearly 1,000 dogs from a suspected puppy mill – reaction from animal lovers was immediate and intense.

Volunteers from the Washington region joined others from Florida and New York who streamed to the rural town of Hillsville near the North Carolina border. Families began calling to ask when they could adopt the dogs. Donations rolled in; PetSmart sent a trailer full of kibble and other supplies.

“It’s been incredible,” County Administrator Gary Larrowe said of the outpouring. Larrowe had declared a state of emergency after hundreds of dogs were found living in filthy cages. Officials said they think it is the largest suspected puppy mill ever found in the state.

Volunteers from a local animal rights group said that when they visited dog breeder Junior Horton’s property in undercover fashion, they were overwhelmed by the numbers of dogs crammed into wire cages in several outbuildings. In one, whelping mothers lay with their distended bellies under heat lamps, waiting to give birth. The dogs appeared to have food and water, but feces under their cages had not been cleaned.

Larrowe said Horton had a local license to run a kennel for 500 animals and had exceeded that twofold. He also did not have the required U.S. Department of Agriculture license that would allow him to sell dogs to commercial operations such as pet stores.

Carroll Sheriff H. Warren Manning said that the matter has been referred to the commonwealth’s attorney. A decision on whether to file criminal charges against Horton is expected within a few weeks.

A man who answered the phone Friday at Horton’s Pups identified himself as Tim Bullion, Junior Horton’s employee. “We just ain’t talking to any press right now or no newspapers,” Bullion said.

Representatives from animal welfare groups from the Washington area began making their way back home Thursday and Friday with dozens of puppies and dogs awaiting homes.

In Montgomery, animal welfare advocates drove the puppies five hours from a staging area in Virginia to a shelter in Rockville. Fifteen workers helped to get the dogs situated in large dog runs with heated floors partly lined with blankets and towels for sleeping.

Some of the animals were reluctant to come out of their carriers at first, cowering when the doors opened. One young female poodle would not budge.

Animal welfare advocates say that puppy mills – unlicensed, illegal facilities that breed large numbers of purebred puppies – have proliferated as demand has increased and dogs have become easier to buy, over the Internet or through newspaper ads. Such animals are often kept in small wire cages, receive inadequate veterinary care and are not domesticated, advocates say.

Undercover investigators from animal rights groups visited Horton’s property several times between April and August and made hidden-camera video recordings of hundreds of dogs kept outside in wire containers. The dogs were all manner of breeds, including Yorkshire and Boston terriers, Cavalier King Charles spaniels, poodles and Jack Russell terriers. The activists showed their video to Carroll officials, who began their investigation.