None. No such salt block or loose mineral mix exists.
They are not and never have been. Ephedrine is not found in medicated salt blocks.
Nowhere. These type of blocks do not exist.
None because no such block exists.
There really is no such salt block or mineral mix. You can check with your veterinarian or those companies that make livestock salt blocks but it's highly likely you will not find such an ingredient in salt licks for cattle.
NaCl. That's it: just plain table salt. And there really is no such thing as a "medicated" salt block.
There are no salt or mineral nor medicated mineral blocks that contain any form of ephedrine in them. Sick animals are treated by antibiotics via injection, not by just giving them a "medicated" salt block.
No because such salt blocks do not exist.
None. No salt licks, mineral blocks, medicated feed or any of that sort have ephedrine in them. This is a myth that has been tested and busted by various scientists that have tried to extract ephedrine from various animal-feed and chicken litter sources. Please see the related question below for more info.
Nowhere because no such salt or mineral block exists.
None. No such salt block, medicated block nor loose mineral mix exists.
Safe-Guard makes dewormer salt licks to combat various parasites that infect cattle. Bovatec makes salt licks with lasalocid sodium for the purpose of helping increase the rate of gain for pasture stocker/slaughter/feeder/replacement cattle. These two brands are the only known "medicated" salt blocks that is made for livestock; all other salt blocks are not medicated and are primarily of trace mineral, iodine, cobalt and iodine or iron, cobalt and iodine. None of these other blocks are termed "medicated." Also, there is no known company that makes salt blocks with ephedrine or any other drug other than the dewormer medicine made by Safe-Guard and increase ADG by Bovatec. Please see the related links and questions below for more info.
Blocks by Bovatec and Safe-Guard are a dark smoky-brownish colour.