By Johnny Dodd
January 21, 2008 12:00 PM

For Hollywood hipsters, the Pets of Bel Air boutique was the cat’s meow. Paris Hilton bought a puppy there. Britney Spears, Demi Moore, Denise Richards and Clint Black shopped there too.

Little did they know that the Humane Society of America was conducting a three-month undercover operation at the store. The reason: “Employees denied that their dogs came from puppy mills [mass breeding farms with alleged inhumane conditions] and … told customers that their puppies had ‘a little cold’ or ‘the sniffles’ when, in fact, they might have been seriously ill,” says Wayne Pacelle, the society’s president and CEO. Records showed that the store purchased dogs from 28 different commercial breeding operations, five of which were criticized by the society, at a cost of about $400 each, then sold them for up to $2,400.

The store was shut down for 24 hours because its business licenses were outdated, but it will stay open because there is nothing illegal about purchasing animals from puppy mills. Owner Jamie Katz declined comment, but the company’s Web site said the store was “horrified” by the report, adding, “We would never knowingly buy a dog from a puppy mill.” The good news: Starting this month, L.A. pet shop owners are required to post on their cages where the puppies were bred.