this is true where short courses of something is given, like regular vets giving one week of baytril at a time for example... but some illnesses need a longer course of antibiotics to make sure treatment is successful. this is usually well tolerated and shouldn't cause any future intolerance, however if it did, exotics/cavy-savvy vets have access to a wide range of treatment so will usually beable to find something else suitable.
alot of times with illness and antibiotics, you have to use them, provide extra support, and worry about the present illness, rather than the future what-ifs
