If urine is old will a drug test show it?

Yes, but only if it has been freezedried and reconstituted within 2 hours before the test. Urine generally is of no use once it has been exposed to the air. It's only good if you don't allow it time & atmosphere to spoil. Anomal urine can also be used, and is undetectable, as they don't test for source, but only what is in it.