When officers arrived Thursday at a Caldwell County kennel, rescuers said, they seized about 300 dogs, including some found living in their own feces with severely matted fur and others with foot problems caused by walking on wire cages their entire lives.

Several dogs were also found dead on the property, according to the Humane Society of the United States, which sent a team to help local authorities rescue the dogs from Mason Creek Kennels on Free Mason Road in Hudson.

Animal rescuers are calling the kennel a puppy mill.

“Mason Creek Kennels has been under investigation for quite a while,” said Caldwell County Animal Control Director Greg Greene. “It’s taken a little while to get enough evidence for the arrest.”

Greene said no charges had been filed against the kennel’s owner, William “Bill” Thomas Allen, but those charges are expected within a week.

The investigation began after animal control got an anonymous tip about the dogs, according to the Humane Society, and an inspection revealed unsanitary conditions and unhealthy dogs.

The Humane Society said the kennel’s owner was selling puppies over the Internet.

The Mason Creek Kennels website claims Allen has 28 years of experience as a dog breeder, and that the kennels are certified by the American Kennel Club.

The site has several photos of puppies for sale, including Yorkshire terriers, Pomeranians, Boston terriers, and French bulldogs. The kennel advertises a two-year health warranty on the dogs it sells.

“We have recently constructed a brand new ‘state-of-the art’ facility which is attached to our residence, which was designed ideally for the rearing of happy, healthy, exercised and socialized adult canines and puppies,” the website says.

But photos released Thursday by the Humane Society show animals kept in dirty kennels or small cages stacked on top of one another.

By Thursday evening, an exhibit hall at the Caldwell County Fairgrounds had become a makeshift shelter where the dogs had been separated into cages that lined the room’s walls. They dogs were taken there by officers to be examined by a team of veterinarians.

“Many of these dogs were living in filthy cages so small that they could barely stand up and turn around,” Kim Alboum, the N.C. director for The Humane Society, said in a statement. “This is precisely why North Carolina desperately needs to pass legislation regulating these breeders. These lax laws have made North Carolina a safe-haven for inhumane puppy mills like this one.”

In 2009, animal rescue workers took about 300 dogs from an alleged puppy mill in Goldsboro. There, investigators found animals with untreated lacerations and skin and eye infections.

Authorities seized nearly 100 dogs from a Guilford County puppy mill in April 2010. Officials said they found malnourished dogs, open wounds, heartworms, a greyhound missing much of her lower jaw and nearly all of her teeth, and a Chihuahua with a puncture to her side that allowed air to leak from her lungs.

Last year, a state bill aimed at combating puppy mills failed for the second straight year. The bill would have regulated commercial dog breeders – defined as anyone who sells dogs and has 15 or more female dogs and 30 or more puppies – and would require veterinary care, appropriate housing and daily exercise. The bill would have also required breeders to register with state authorities.

Opponents argued the bill would attack reputable breeders.

Court records from 2010 show Mason Creek Kennels owes the IRS more than $7,200, which has not yet been paid.

Allen, its owner, was recently charged in connection with worthless checks. One case was waived, and the other is pending, records show.

He could not be reached for comment.

Want to help?

The dogs will stay at the shelter set up at the fairgrounds until released by Caldwell County authorities. Over the next few days, they were be examined by veterinarians, and after an evaluation, the dogs will be sent to the Humane Society’s emergency services partners and placed into adoption.

Anyone who wants to make donations for the care of the dogs can send checks to the Caldwell Humane Society at PO Box 1991, Lenoir, NC 28645 or contact Donna West at 828-292-2925 or email caldwell4pets@gmail.com.

Staff researcher Maria David and staff writer Steve Lyttle contributed.