LANGLEY, B.C. -- Some of the most expensive and sought-after breeds of dogs are being nursed back to health in Vancouver after being seized from an alleged puppy mill in nearby Langley.

Sixty-six animals, including 34 puppies, were seized Thursday in what British Columbia's SPCA said was one of the largest puppy mill seizures in the province's history.

Veterinarians and staff at the society's Vancouver shelter have been working non-stop to care for a range of injuries including broken limbs, missing eyes or ears, malnourishment, infections, abscesses, and psychological issues, Marcie Moriarty, the society's chief prevention and enforcement officer, said Tuesday.

"Many others show signs of fearfulness due to lack of socialization," Moriarty said.

Breeds that were seized include standard and miniature poodles, Old English sheepdogs, Bernese mountain dogs, soft-coated wheaton terriers and Portuguese water dogs.

A member of the public who was checking the background of a dog advertised for sale on a social networking site alerted authorities to the plight of the dogs.

"A key step in shutting down puppy mills is for those who are purchasing animals to be educated and aware of the signs of unscrupulous operations," Moriarty said.

"We have to make it clear to unscrupulous breeders who sacrifice animals on the altar of profit that this type of neglect and cruelty is not acceptable to British Columbians."

Society spokeswoman Lorie Chortyk said at least two people are believed to be involved in the operation.

The SPCA is preparing a report for the Crown and is recommending charges under the Criminal Code as well the Prevention of Cruelty to Animals Act, she said.

The highest penalty is five years in prison, a $75,000 fine and a lifetime ban on animals, Chortyk said.

"We're hoping, given the severity of this case and the fact that this is such a sophisticated operation, that Crown counsel will approve charges and that the sentencing will reflect the degree of suffering for these animals."

She said the SPCA received a complaint about the same property in 2009 and again last year but it's often tough to investigate allegations because some puppy mill operators know how to evade detection.

"They know we can't go on without a warrant so when we go they say, 'This isn't a good time, come back tomorrow.' By the time we go back they've moved the animals."

However, in this case a woman who was on the property to buy a puppy saw enough before calling the SPCA, which meant the agency was able to access the property without a warrant, Chortyk said.

"It's a classic puppy-mill situation where dogs are bred repeatedly. They were kept several dogs to a cage, stacked up in unheated dark buildings with dangerous ammonia levels from the urine and their fur was matted and caked in feces and urine."

Puppies that typically cost about $1,000 at such operations may appear healthy but are often sick and have genetic issues from overbreeding, Chortyk said.

She said tell-tale signs of breeders that churn out "quick-sale designer dogs" include not letting potential buyers see the property or a puppy's parents, not providing veterinary records for the dogs or meeting a buyer off site.

The dogs and puppies seized last week continue to receive vital care and are not yet available for adoption, but the Vancouver shelter is requesting donations of blankets, towels and dog beds to help keep them warm and comfortable as they recover.