First, WELCOME to YT
!!!
I know you'll get some great advice regarding the options with liver shunt. I haven't had to personally deal w/ LS, so I'll leave the good advice to those who have experience. There are so many people here who have gone thru what you're going thru, and their yorkies are doing just awesome!
Would love to see some piccies of your kiddo sometime, I bet he's a doll. Tell him Happy Belated Birthday!