Diagnostic testing is a tool widely used by veterinary practitioners. A diagnostic test can be as simple as a visual observation, or as complex as a trichomoniasis testing regimen.
“Diagnostic testing is probably also one of the most misunderstood tools in our toolboxes,” said Carla Huston, PhD, Dipl. ACVPM, Mississippi State University, speaking at the 2012 Western Veterinary Conference in Las Vegas last week. “Our clients expect us to perform a diagnostic test and have the results quickly, accurately, and cheaply.”
Huston said that in food animal practice, veterinarians test for disease for many reasons:
- To confirm hypothesis on the cause of an illness or disease
- To predict severity of an illness and provide a prognosis
- To examine response to treatment
- To investigate changes in incidence or prevalence of a particular disease
- To monitor and identify outbreaks and epidemics
- To enhance marketing opportunities, improved economics
- To evaluate the effectiveness of a herd health or disease control program
Disease control testing
There are other regulatory diseases such as tuberculosis and trichomoniasis that require a good understanding of the test characteristics. “States may have specific testing requirements that must be met, so it is important to know the intentions of the testing, and whether or not the animals will require testing prior to movement,” Huston explained.
“Using these two diseases as examples, we can evaluate diagnostic testing methods used and come up with testing strategies to assist our clients.”
Before testing a herd under a disease control program, Huston said several questions must be answered:
1. Why are the herd health programs needed?
2. Which diseases should be considered?
3. What type of data should be included?
4. Who is going to use this information?
5. What will be the uses of the test results?
6. Will the health program have local, regional or national implications?
7. How is this program going to be financed?
8. Is the existing farm infrastructure adequate to support the program?
9. How will the testing program’s efficacy be assessed (validated)?