These two dogs were among 157 rescued from a puppy mill north of Montreal. ((CBC))

Animal welfare authorities in Quebec have raided a second puppy mill in less than a week, rescuing more than 150 dogs from squalid conditions north of Montreal.

SPCA workers searched the private puppy mill Wednesday in Lanaudière after receiving a tip.

They found 157 young dogs living in squalor, "crammed into tiny wire cages, stacked from the floor to the ceiling," said Rebecca Aldworth, director of animal programs for Humane Society International Canada.

Many required medical care, she said. Several other dogs were found dead on the property, in St-Lin. Most of the puppies were taken to the SPCA in Montreal.

It's the second time a large, Montreal-area puppy mill has been exposed by the SPCA this week.

The raids will hopefully discourage people from buying dogs at pet stores, which often procure puppies from mills, said Alanna Devine, acting director at Montreal's SPCA.

"It's really important for people to realize what a wide-scale problem this is," she said. "This is just the tip of the iceberg."

It's difficult to crack down on mills because provincial animal welfare laws aren't always enforced, Devine said.

"Ideally, if the SPCA had the mandate to enforce both the criminal and animal welfare laws, we'd be able to do much more," she said.

"In every other province, there [is] government funding in order to enforce legislation, and it is time that Quebec turn around, and realize that we have a problem," she said.

No charges have been laid in the Lanaudière raid.

Last Friday 118 animals, including cats, dogs and rabbits, were rescued from a mill in Rawdon, north of Montreal.