Welp, I'll go contact our three exotics vets and let them know that every single antibiotic we've used for over a decade is a bad antibiotic. And then I'll call my doctors and tell them that every antibiotic I've ever been on is also a bad antibiotic.
Symptoms should start to disappear within 2-3 days of an antibiotic being given, or it is ineffective to that infection. However, it's unwise to stop an antibiotic just because the symptoms have disappeared -- it's much more common to run an entire "course" of antibiotics, which is typically 10-14 days (14 days being more common with rodents because of their preponderance of hiding symptoms as soon as they feel better). That's why when you have strep throat, they give you 10+ days of antibiotics and there's a big warning on the bottle to take the entire course, even if you feel better. Stopping as soon as symptoms disappear typically leaves some active infection in the body which has a chance to mutate and become less affected by common antibiotics.
Unfortunately, this is something that we've seen happen, and frequently animals come in that have been on several short courses of common antibiotics, and then we're forced to run a sensitivity culture on their discharge to figure out what novel antibiotic will work on the "super" infection.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry