What is the Role of Veterinary Epidemiology?

Begin by reading this topic in the workbook (or online)

The third major function of epidemiology is to apply our results, and then to evaluate the effectiveness of interventions and strategies for improvement of animal health and welfare.

With observational epidemiology, we can assess the impact of animal health services on the health and productivity of an animal population.

Observational Epidemiology Example

With interventional epidemiology, we can assess the effect of a specific animal health intervention.

We can use individually-randomised controlled trials (where each participating animal is randomised separately, as an individual) to compare a new treatment with an established one.

Interventional Epidemiology Example

Sometimes it may be better to randomise at the level of the herd rather than the individual animal.

For example, when assessing the impact of wildlife vaccination on tuberculosis in cattle one would randomise herds rather than individual cattle.

So in this case, a number of suitable herds would be selected, and then each herd (with all its inhabitants) was randomised to have the local wildlife population vaccinated or not.

We will discuss these in Chapter 17 --Intervention studies.

The challenge of epidemiology is that we must make these comparisons not in a highly-controlled environment such as a laboratory, but in a real-life situation where there is a lot of "background noise". We work with real populations and have to compare exposures and outcomes in situations where there may be many sources of confusion and error. This is a particular problem of observational studies.

An important part of the process of learning about epidemiology is to understand how such mistakes may arise and to know how to minimise them. We will return to these issues later in the course.