I thought liver shunt showed when they're puppies
I noticed that Nicky trembles slightly some times. So subtle that only I noticed it and I was beginning to feel self-conscious around people who think I tend to over react when it comes to my babies
Well...I watch him closely for some time to see if it was because he was cold, sick, nervous, etc. After about 2 months of watching him I realized that none of the above were the reasons why he shakes a bit, so I took him to the vet and explained, best I could, what is it that I see.
Blood work was done: No eating (before the first draw of blood) for 12 hours and then I fed him. 2 hours later the second drawn of blood to compare.
The vet found something suspicious, which she says could be Liver Shunt
But I thought Liver Shunt only showed on puppies

We're taking our baby-boy for an ultrasound to rule Liver Shunt in or out. Vet says if positive, Nicky may have to go on meds and special diet, or he may need surgery
Our vet said, in a matter of fact way, "see if you can get an appointment today for the ultrasound." I don't want to take it as: it's very important, an emergency, but we don't want to scare you kind of thing

Should I take it like that?
How dangerous is this Liver shunt and or the surgery? He'll be 4 in August. Should I freak out now or could I do it later?
Could it be his Pancrititis acting up?
This is very scary for me
What do you think? Any advise, suggestions, guidance? I appreciate any. Thanks