This is ridiculous, heroin is brought into this country as a street drug, by usually the CIA, usually from Afghanistan up through Turkey, then put on our streets. This drug is the problem with overdose, not the meds from the vet or doctor. When a person is on pain management from a pain clinic, it is very carefully tracked, patients are tested for use, they are put under strict compliance and conditions by the latest laws from federal government, paperwork tripled and special handling has been already a burden to doctors etc. 
The street heroin is entirely a problem in itself, it's everywhere, it's cheap and anyone can find it on the streets, most users do not go from a hospital emergency room, run out of pain meds and go out and get heroin, there has not been careful research done on this street drug and its users whatsoever! And the dealer's, and where they come by the drug in the first place!