If you have his KC registration you can tell which breed supplement he was registered in and from that what other puppies were recorded in litter. The change of ownership to the new homes may be in the same issue or later depending on when they were sold/registered but this only shows the new owners names, no addresses,so they could be anywhere.
Someone on here kindly gave me the details of the other pups in Jaspers litter.
The breeder would of been best bet if they are willing to put you in touch with other owners or forward a letter perhaps - depends on relationship with the breeder I guess
if they've stopped breeding possibly they can't be bothered.
Can the Kennel club help?
