Records are music discs that you can play for your dogs. In the DS version, the records can scare your dogs, make your dogs angry, reset your dogs' mood, or convince them to bark along. In the 3DS version, the records can make your pets do a specific dance routine, depending on the record, or lull them to sleep. In the DS version, the Naptime record can lull your puppies to sleep just like the Up in the Clouds record can in the 3DS version. A few records are exclusive to certain game versions (In Nintendogs they are called Archie's four secret records), for example, the Shredded Fur Record is exclusive to Labrador and Friends.
Note: Your pet(s) will only do these activities if you are playing the record with it showing on your screen- your dog will act normal if the record is being played in the backround.