Puppy pipeline: How we reported the story

To report this story, The Times filed public records requests to all 50 states for dog export records, the 58 counties in California for dog import records, several animal control and law enforcement agencies for investigative files and reviewed U.S. Department of Agriculture inspections and other documents related to its licensees.

Thirty-three states provided one or more years of certificates of veterinary inspection, which document the movement of dogs and their health status. The remaining states considered the records confidential, had short record-retention periods or charged exorbitant fees to collect the documents. In all, The Times collected nearly 60,000 certificates for dogs approved to travel into California, reviewing each page to determine the number of dogs in any given shipment. A single form could include anywhere from one to dozens of dogs.

The Times counted roughly 88,000 dogs approved to travel to the state since 2018, logging each entry by year. The analysis represents the clearest accounting yet of dogs coming into California from other states.

Each state has multiple versions of travel certificates — some are digital, and many are handwritten. Some states keep the records in cardboard boxes at off-site storage facilities; others keep them digitally or log them into spreadsheets.

Some of the travel documents listed microchips. The Times ran hundreds of microchip numbers through public microchip databases, some of which make owner information public. Pet microchip company Peeva helped put The Times in touch with pet owners whose microchips were registered with the company and appeared on travel certificates. By tracking the microchips, reporters were able to learn where dogs ended up in cases where the destination listed on the travel certificate was a fake name or nonexistent address. Reporters also identified pet owners through civil and criminal court records.

The Times attempted to interview breeders across the country, including during a reporting trip to Midwest states. Reporters attended a dog auction in Missouri to see the condition of breeding dogs being sold.

In California, reporters visited numerous locations listed as the destinations for bulk shipments of dogs.

The Times also pored through thousands of pages of USDA investigative reports and inspection records posted online, as well as court documents across several states. Two animal welfare groups — Bailing Out Benji and the American Society for the Prevention of Cruelty to Animals — also shared records provided to them by the USDA.

This story originally appeared in Los Angeles Times .