Personally, I would not go back. I just do not like to purchase from breeders that have THAT many dogs. This is what wikipedia encyclopedia says about mills/BYB.
http://en.wikipedia.org/wiki/Puppy_mill
Puppy mills (known as puppy farms in the UK and Australia) are dog breeding operations that are considered by some to be disreputable and sometimes hazardous to the health of the animals due to the conditions of the breeding kennel. The term originated among critics of such operations. Small-scale operations where dogs do not receive adequate health care or good sanitation are usually called backyard breeding; the terms are akin but not synonymous. The largest concentrations in the USA are allegedly in Lancaster County, Pennsylvania and rural Missouri.
Reputable breeders raise their animals in humane conditions, provide good socialization and often formal training, and adhere to the breed standard. They are knowledgeable about major health problems associated with their breed, and with the principles of genetics, frequently undertaking specific matings to produce or refine particular desirable characteristics in their dogs. They are also sensitive to the requirements of their breeding adults — who may also be breed or performance champions — and the puppies they produce. Reputable breeders frequently screen potential customers rigorously, and usually provide a pedigree and health guarantee with their puppies.
Although many responsible breeding operations tend to be small,
size alone is not an indication that a particular operation is a puppy mill. Rather, puppy mills are characterized by ignoring duties that are standard among responsible dog breeders. They may keep their dogs in overcrowded, unclean or otherwise inappropriate surroundings. The puppies they produce may be improperly socialized or may suffer from health problems which are often not disclosed to purchasers. Their breeding animals may also suffer, with females sometimes forced to undergo repeated pregnancies too quickly to fully recuperate between them.
Puppy mill operators may misrepresent the breed of dog being sold, and adult puppy mill dogs may exhibit characteristics uncommon to their advertised breed. Unlike the puppies produced by reputable breeders, the vast majority of puppy mill animals are sold to pet stores. Puppy mill operators are frequently accused of being motivated only by profit rather than a commitment to the breed or any empathy for the animals in their care.
Purchasing dogs, especially those claimed to be purebred, from a pet store is strongly discouraged by reputable breeders and animal shelters. While many pet stores claim to purchase dogs from "local breeders" instead of puppy mills, this is often untrue or is a difference in name only, as reputable breeders generally do not sell animals to pet stores. The phrase "local breeder" may also refer to backyard breeders.
The U.S. state of Kansas has enacted a law to protect puppy mill owners by making it a felony to photograph a puppy mills and facilities.