Countries will have different rates of SM according to what cavaliers were exported from the UK in the past.
Some countries seemed to be badly hit before it became so widespread in this country, probably because they had a much smaller cavalier population that was very closely linebred to 80s and 90s UK imports that carried the SM genes.
Now, with the condition so prevalent in our stock, & unscanned UK cavaliers being sold all over the world and being used for breeding, SM will rapidly become common in every country
Cavaliers......Tommy Tuppence 2000-2012 and a half share of Faith.
Japanese Chins.... Dandy, Benny, Bridgette and Hana.