Veterinarians can be in theory a risk for animals if good practices are not followed. In western countries veterinarians that go to big commercialised farms take the highest precautions when entering the farm premises. Veterinarians put on different clothes and take a shower before entering and after leaving the houses. In less developed countries veterinarians are usually not specialised and the opportunity to take the precautions made by their western fellow partners is not possible. Risks of cross contamination in these circumstances are possible, but still very small.
In Europe veterinarians follow a Code of Good Veterinary Practice Code (GVP). This code consists of rules to ensure that veterinarians work clean and that veterinarian’s use there experience when prescribing drugs. These veterinarians work with a Formularium system. This system is a guideline for prescribing drugs for animals. It leads the veterinarians to a first second and sometimes a third type of drug, dependent on the symptoms and severity of these symptoms. This in combination with the experience of the veterinarian ensures a good choice of medicine. Not only to heal the animals but also to ensure that the drug will not be overused and lose its potential. These Formularia are updated every few years, because bacteria and viruses mutate easily and do not react the same to one medicine over the years.