I think Don has raised a very good point there, reinforced by KITKATs story....
Maybe thiaminase is more harmful to juveniles than it is to adults. When I think back now, I only remember juvenile snakes, raised on the wrong kind of fish, suffering any symptoms. Maybe that's a dangerous supposition, I certainly don't want to be the one to research it!

Excellent topic by the way, Kyle.... and well presented.