Can you elaborate? I've always thought you needed a script, and have occasionally not taken prescribed antibiotics just for a SHTF situation. (Not good, I know.)
http://www.calvetsupply.com/category/Antibiotics
Made in the same plants human ones are, just labeled differently.
I also purchased a nurses guide to drugs and a physicians desk reference. I don’t plan to use them unless I can’t get doctor. Dosage is important of course.
I can’t do the link here on my tablet, but you get the idea...http://www.aquaticpharmacy.com/product-info.html.
I haven’t researched, but when I bought a supply last year, this was the cheapest place by far.
Agricultural supply stores often have antibiotics. The stuff for animals is the same as what’s used for humans, and no script needed.
Depending on what form you get it in, you may want a scale to measure out doses with. Calculate by body weight.
I did that once for my cat.