Preventative screening for food contamination

I realize the vet knows what to check. But I would like to know in
advance what I should be expecting them to check.

Bloodwork for sure.
Urinanlisys for melamine right?
Anything else?

I know our vet sends out for labwork. Is the urine test something that
would probably go out too, or is it likley to be done inhouse?


Should I have him retested later even if things check out fine this
time?

Are there any recommendations being posted for pet owners to do to
make sure their critters are all okay?

I thought I was lucky (and I may still be), but I don't want to take
that chance.