Court Upholds Law to Prohibit the Sale of Puppy Mill Animals in Chicago : The Humane Society of the United States www.humanesociety.org/news/news_briefs/2015/11/chicago-puppy-mill-dogs-sales-banned-110615.html?credit=web_id93480558#.Vj2ygBGA7C4.twitter Under a court order, pet stores in Chicago are still prohibited from buying puppies from large-scale commercial breeders, also known as puppy mills. Several pet store owners challenged the ordinance that was passed last year. The Humane Society of the United States and The Puppy Mill Project submitted an amicus brief in support of the city and a federal judge has dismissed the case.