Just thought I'd add my experiences of C&S for bacterial infections in rabbits...
IME most rabbit C&S tests show sensitivity to baytril, when in reality we know that illnesses such as abscesses and snuffles are very rarely cured by baytril.
So if you have a C&S done which shows baytril to be effective, you'd be well advised to use another antibiotic as well.
The bacteriocidal effect of Baytril depends on the drug level where the infecting bacteria are. It is a very good antibiotic for bacterial skin infections & is effective against a wide variety of bacteria.
Abscesses & snuffles present a particular problem of getting sufficient concentrations of antibiotic to the place where the bacteria are. These situations are well known to the prescriber, who specializes in rabbit illness.
I understand that vets are supposed to use an antibiotic licensed for use in the species 1st. & only proceed to others when the licensed drug fails to work. Some vets adhere to the regulations strictly, whereas others follow their experience. The regulations are in place to prevent the widespread use of human antibiotics in animals & the emergence of bacterial strains resistant to human antibiotics.
It is more than useful to know that we are dealing with MRSA in this situation because it is resistant to so many human antibiotics.
I agree that c&s can be misleading at times, as can any test.