The RCMP and the New Brunswick SPCA seized 149 dogs from a suspected puppy mill near Edmundston on Thursday.
Chief inspector Paul Melanson told CBC News that the SPCA and police executed a warrant in Saint-Basile.
The dogs were the second lot seized under a new provincial law designed to crack down on puppy mills.
There are more than 100 older dogs, dozens of puppies, and some females are just about to give birth.
Melanson said the dogs have ear and eye infections and some needed urgent vet care.
"We had received a complaint from the public about the conditions, the fact that the dogs were living in their own filth," Melanson said. "They were severely matted and were in bad need of being bathed because of the feces on the bodies themselves."
Melanson and the RCMP raided the St. Basile kennel under a new provincial law that requires inspections and licensing. The kennel got a licence last year but it had expired.
"The housing conditions were poor. The doghouses themselves were in a complete state of disrepair so they were about to fall down," said Mike Murphy, executive director of the New Brunswick SPCA.
"There was no heat, no ventilation, no bedding for the animals or anything that you would consider normal for an animal."
Melanson said the new regulations for pet establishment licences give protection officers more power to make inspections.
But he knows there are more puppy mills out there because it can be big money.
"Prices would range from anywhere from $350 to $600 to $700 for a pup."
"I don't think it's ever going to be something we're going to find every backyard operation that's been run like this. You know, we're dependent on the public letting us know when they find something that they feel is unacceptable," Murphy said.
Charges are pending against the owner of the dogs, and also against the owner of 40 other ones seized from an unlicensed kennel last week in the same area.
Melanson said the minimum fine is $500 and the maximum is $10,000 and a prohibition from owning dogs.
The dogs are now being triaged at an undisclosed location. After they're treated, they'll be distributed to shelters across the province.