First guess empirical antimicrobial therapy is often necessary both because of a client's financial restrictions and because of the need to begin treatment as a life-saving measure before the results of culture and sensitivity testing become available. However, if you expect the drug to work, an attempt must be made to identify the microorganism(s) involved and their likely antimicrobial resistances.
Two major considerations in large animal practice are cost and practicality. Although you should help the farmer consider the benefits of antimicrobial therapy on a basis of economic returns, you also have a legal and ethical responsibility to relieve animal suffering. It can be very difficult to reconcile these two roles. You should also bear in mind public health and the chances of significant resistance developing.
Cooper, BS (ed) Antimicrobial Prescribing Guidelines for Veterinarians, 2nd ed, Postgraduate Foundation, University of Sydney.
Although this book is Australian, most of it is just as relevant to NZ, particularly the cattle section.
Cardiovascular system
Skin
Respiratory system
Urinary tract
Central nervous system
Gut
Eye
Reproductive tract
Bone and joints
Udder
