This project will generate epidemiological data on the bacterial species associated with different infectious diseases in horses in south eastern Australia, and the antimicrobial drugs to which these isolates are susceptible. This information is of vital importance to equine veterinarians as treatment is often, of necessity, initiated prior to receipt of laboratory results from individual patients. In such cases, the best available information on which to base drug selection is data from similar patients in the same location. This data is simply not available in Australia, and extrapolation of findings from other parts of the world is likely to be misleading. Collation of such data over time allows recognition of changes in antimicrobial susceptibility, which is critical for recognition of the emergence of antibiotic resistance in bacteria. A second outcome from this study will be comparison of more advanced laboratory techniques available for the identification and antimicrobial susceptibility testing of bacterial isolates with those more traditionally used in veterinary diagnostic laboratories. If the difference between existing and advanced techniques is trivial the expense of ‘upgrading’ existing laboratory practices would be unjustified. However, these techniques promise efficiencies in sample handling, more rapid ‘turn-around time’ and greater accuracy which are potential advantages to equine veterinarians in offering improved treatment to their patients and better outcomes for horse owners.