Indeed, our vets for our raptors often voiced similar concerns, where people just expect that vet med scripts should just be handed out whenever for whatever the pet owner wants... However, FDA guidelines are rules apply to vets just as well as pharmacists, psychiatrists and family practitioners. As far as the fed is concerned, drugs are drugs, and they want to control anything more powerful than asprin. As a result, ANYTHING much more powerful that asprin is subject to federal regulation, and those rules, laws, and punishments aren't less just because pet owners think they know better than the vets or docs or government. No differently than any "people Dr.", the vet is under just as much risk if s/he wrongly provides you with a script, sample, or bottle for any drug or medication on an FDA "schedule" that you don't have a valid use for that is consistent with its FDA approved use. Interceptor is not approved by the FDA for fish... It's approved for dogs, and even then they found something about it to be scary enough to decide it shouldn't be left up to the common citizen to make a proper decision about what to do with it; either because they might hurt themselves or their pet without proper veterinary care and regular checkups.
I've been on both sides, though as a falconer, even with a new vet all I had to do was bring the bird to the vet and they'd say "er, I don't know **** about this thing... here, you've got a state and federal license, you obviously know more about it than I do, here's your drugs," but that has a lot to do with the fact that I can bring them approved research to account for my medical diagnosis and they can verify many of these meds' usage on birds and raptors in their own books. Vets, however, don't know much about fish, generally, and they can't just be expected to believe because you say so that interceptor kills red bugs and and that you do indeed have said red bugs, any more than they should be expected to just take my word for it when I walk in that I have a doberman puppy whose ears are cropped and I need a bottle of ether in order to reapply the bandages, esp. if they've never seen me before and didn't crop said puppy's ears... Why should they take my word on it and just hand over a script for something that could get their license revoked and send them to jail. Even if they are also a hobbyist and know you and can confirm you have red bugs, still, prescribing any medication inconsistent with it's approved usage could get them in hot water, so please, do, take it easy on your vet, they're doing the best they can do - it's not as if they're super highly paid and regarded as paragons of society, as some people treat surgeons... I honestly have more respect for vets who do what they do out of love and compassion (not because they're going to get rich), unlike many Dr.'s I've met who were in it primarily for money and success, practicing guess-work in a white coat with a fancy degree.
The real question here is reliability and integrity of any Dr. who will just give you Oxy.
