SAO is the Russian correct Abbrievation Sredneasiastskaia Ovtcharka The "T" is silent and only used in Europe. Correct Translation is CAS Central Asian Shepherd In the US UKC We use CASD Central Asian Shepherd dog as well as other countries. http://www.ankc.aust.com/centrala.html CAO is the misnomer incorrect half translation used by Americans to lazy to translate the whole name or pronounce the Ovcharka Same Applies for Caucasian. Russian is KO for Kavkaskaya Ovtcharka English would be correct as Caucasian Shepherd "loosely" and in US history it was has been called the CMD Caucasian Mountain dog In addition to the CAS - the Russian standard has been different for 7 years then the FCI and USA standards thus the SAO/CAO will one day have a separate breed if FCI refuses again to accept the changes. Breeding to 2 different standards will create 2 different breeds.