According to Wikipedia, the American Bobtail Cat is not related to the Japanese Bobtail Cat in any way. They came from different genetic lines even though both have similar builds and colorings.
pagkakasundo sa Wikipedia, ang america Bobtail pusa ay hindi isalaysay sa ang Japanese Bobtail pusa di sino man daan. sila kamelyo sa iba heneral tutupan patagin kahit na kapuwa may katulad magtayo at colorings.