The term puppy mill has been applied loosely to many undeserving people who breed large numbers of litters a year to improve a specific breed. That alone does not constitute a puppy mill. While these people may breed more litters per annum than most, their dogs are properly screened and tested for any genetic faults, are current on vaccinations, have nutritionally balanced food and clean water at all times. The puppies are socialized from a very early age, live in a clean environment with plenty of daily exercise and human interaction.
Potential buyers are able to see both parents of the puppies in most cases.
This kind of breeder screens and interrogates the potential buyer until the breeder feels comfortable that the person will provide a proper good loving home and make a commitment to the dog for the duration of it's life. This type of breeder is not a puppy mill. Sometimes these dogs are crammed several to a crate and may even have bodies of dead dogs in their confined areas. Most of the time there is no water, and they are walking through feces and urine and are disease infested. Most of these dogs never leave their enclosure and frequently die from exposure to the elements.