I don't believe it's that common. Why are you concerned? I know at least 3 yorkies on YT who have had it. One did die even after surgey, But 2 are living amazing lives - for more info you could contact Babybear's mom, Val, her user name is Mybaby4m3 or this is Babybear's dogster page where she has all his videos and his amazing story
Dog profile for Wheelie Boy Babybear® , a male Yorkshire Terrier
or you could contact Bleu Boy Barber - Vicki could also share her experience and Bleu's amazing story which was told here in full
http://www.yorkietalk.com/forums/sic...ry-urgent.html
What is going on?