Inspections by the Environment Ministry and local authorities have found that the dates of birth of puppies and kittens auctioned for pet dealers were highly likely to have been falsified in many cases.

The inspections, conducted at 19 auction venues in nine prefectures — Hokkaido, Miyagi, Saitama, Kanagawa, Tochigi, Shizuoka, Aichi, Osaka and Fukuoka — found records showing that many puppies and kittens were born on particular days of the week, raising suspicions that the dates of their birth were falsified. The ministry announced the results of the inspections Thursday.

The ministry believes that animal breeders altered the dates of birth in order to put puppies and kittens up for auction even though they were younger than allowed under the law.