Diagnostics is the science and practice of identifying the cause of a disease or illness. Veterinarians can diagnose disease in farm animals and there are a range of tools and tests available to help them make an informed decision over treatment and management of disease. This requires taking samples such as bloods, swabs, postmortem tissue samples, or even observing clinical signs and behaviour. Various laboratory tests are performed on the samples taken, depending on the pathogen that is suspected to be present. Often, diagnostics are used to rule out the likelihood of a disease as much as identifying the causal pathogen.
The result of a diagnostic test can lead to more responsible treatment decisions as the causative pathogen can be treated in a targeted, effective manner. For example, if a virus is detected, antibiotics will not work and are an inappropriate treatment.
Culture and sensitivity testing on bacterial disease is recommended as it informs antibiotic treatment and ensures the right product is used for the right disease. Diagnostic tests can also identify certain animals that may be harbouring disease and inform management decisions, such as culling PIs in a BVD eradication programme.