Ecellent board really helpfull

I've a garter snake, kinda tough to find what kind of Thamnophis it is...I used to have Radix and checked...but this is different onight she ate 3 earthworms and 2 fishes ( Poeciliopsis gracilis)

So this thing about thiaminase just started to really worry me...do you think this fishes have a lot of this?

Oh...I almost forgot a picture of the snake...(I know it's terrible but I promise a better one) and the terrarium