The Humane Society said today that Petland stores are selling puppies from so-called puppy mills, but telling customers that the dogs come from good breeders.

The animal-protection group made the charges at a news conference in Washington after an eight-month investigation of the chain. It involved 21 Petland stores, including two Minnesota stores, and dozens of breeders and brokers.

The two Minnesota stores are in Shakopee and St. Paul.

The Humane Society says dogs at the mills were found in dirty cages and cages with wire flooring so large that the puppies' paws and even the paws of the mother dogs would fall through.

In a statement, Petland says the company does not support substandard breeding facilities and provides each store with guidelines on humane care of animals.