While some epidemiological work has been conducted on Spotty Liver Disease (SLD) since the identification of the causative organism, this has been of the descriptive kind only. Descriptive epidemiology seeks to examine factors associated with the host, the causative organism and the environment.This has only partially been achieved so far.

Analytical epidemiology on the other hand, involves the application of surveys and observational studies in the actual population at risk. The major purpose of analytical epidemiology is to provide information on which “rational decisions for the prevention and/ or control of disease in animal populations is based” (Martin et al., 1988).

This research will lead to identification of “key determinants” of SLD. Key determinants are those factors which may be amenable to management so that the disease outcome can be modified. These will lead to better management of the risks of SLD in free range flocks, reduction in the need for extensive and often repeated antibiotic use and improve the potential response to an SLD vaccine.