Quebec agriculture officials say they uncovered one of the biggest puppy mills in the province's history after finding more than 200 dogs and about a dozen cats during a raid Friday in the Eastern Townships.

They found the animals on a farm called  P'tites Pattes Poilues, situated on Route 220 in Bonsecour — between the cities of Granby and Sherbrooke.

“They were deplorable conditions — one of the worst I’ve ever seen,” said Rebecca Aldworth, executive director of the Humane Society International.

The 220 dogs — many of them pregnant females -- and about a dozen cats were all living inside a barn.

Aldworth said the animals were covered with infections, and many had patches of fur missing.

More than 30 agents from Quebec's agriculture ministry, the Humane Society International and the local SPCA were involved in the raid.

Officials say they believe the site did not respect the norms outlined in provincial regulations that ensure animal welfare.

“Following a routine visit, we decided to launch this intervention,” said Cathy Bergeron, spokeswoman for the Société protectrice des animaux (SPA) de l'Estrie.

The animals were seized and moved to shelters, where veterinary treatment will be provided.

The cats were brought to the SPA in Sherbrooke, while the 220 dogs were sent to the agricultural ministry’s emergency shelter.

“Regardless of where the animals are sent, they will all be examined. They will receive the care they require,” Bergeron said.

Inspectors will complete a report in the coming days and transfer it to a Crown Prosecutor, who will determine whether or not criminal charges will be laid.

Under provincial law, anyone found guilty of running an illegal puppy mill could face a fine of up to $12,000.