The drugs in a hospital aren't illegal, but stealing them is. The feed and grain store is an interesting idea, but I don't believe that animals get vaccinated for tetanus, so I am not sure tetanus toxoid would be available. And are prescription medications (such as an antibiotic) sold at feed and grain stores? In my experience, the vet has all medications needed on hand. I had one time where she wrote a prescription and I had it filled at the drug store (this was for my dog).
Leslie
Horses, cattle, and sheep get vaccinated for tetnus, esp. after and injury or a proceedure, like castration or docking tail in the case of sheep, though the vaccine is labled NOT FOR HUMAN USE. Horses are recommended to be annually vaccinated for tetnus usually combined with a sleeping sickness vaccine. Dogs do to but not usually until there is an injury
Feed and Grain stores and Elevators can carry vaccines, growth implants and some antibotics like penicillin and Liquamyacin, but not the drugs like tranquilizers-those kind have to be prescribed by a Liscensed vet.