The dogs were found covered in layers of filth and matted hair, and underneath that, you could feel their ribcages.

That's how Scotlund Haisley, president of nonprofit Animal Rescue Corps, described the condition of about 100 dogs rescued from a dog breeder in Humboldt, Tennessee, on Wednesday. He said the conditions were typical of a so-called "puppy mill."

"You could feel the ammonia burning across your face," Gibson County Sheriff Paul Thomas, whose office worked with ARC on the rescue, told a local ABC affiliate. "The feces, the urine, it's horrible."

One of the dogs rescued in Wednesday's raid. Photo credit: Amiee Stubbs for Animal Rescue Corps

The raid, called "Operation Home for the Holidays," began after Animal Rescue Corps received a tip and sent an undercover investigator, posing as a potential buyer, to collect evidence. That evidence was brought to the sheriff's office, which executed a search warrant, leading to Wednesday's raid.

“These dogs have been suffering from various untreated illnesses on this property for a very long time,” Haisley said in a news release. “A lot of suffering ended here today.”

One of the dogs rescued in Wednesday's raid. Photo credit: Amiee Stubbs for Animal Rescue Corps

Among the rescued dogs -- both puppies and full-grown -- were Pomeranians, Maltese, shih tzus, poodles, Boston terriers, Yorkies and "one pit bull," Haisley said. "No one knows why there's a pit bull in a cage in a puppy mill."

One of the dogs rescued in Wednesday's raid. Photo credit: Amiee Stubbs for Animal Rescue Corps

In addition to being malnourished, an initial examination showed, the dogs were suffering from parasites and eye infections, bald patches and urine burns.

On top of that, Haisley told The Huffington Post, "The large majority of the dogs have never been handled. They certainly don't know what compassion is."

The breeder has been arrested, but his or her name has not been released. The sheriff told news outlets that animal abuse and neglect charges will likely be filed Thursday.

Haisley said the breeder has surrendered ownership of the dogs to ARC.

One of the dogs rescued in Wednesday's raid. Photo credit: Amiee Stubbs for Animal Rescue Corps

The dogs will eventually be available for adoption. For now, they've been transferred to an emergency shelter, where they will receive grooming and medical treatment -- and what might well be their very first moments of human affection.

UPDATE, 1:50 p.m.: Sheriff Paul Thomas told The Huffington Post that the dog breeder's name is Laura Morris, and that she is being charged with 95 counts of animal cruelty.

As of Thursday early afternoon, "she's incarcerated," Thomas said.

See more photos from the raid, and keep tabs on the dogs, over on the Animal Rescue Corps Facebook page.