The Key Concepts of Animal Models

Translational research makes use of animal species based on various scientific parameters to ascertain their phylogenetic, physiological, and anatomical closeness to the targeted species (most often humans) and to use any or all of these outcome measures to forecast and determine the effectiveness of potential therapies. When the animals aid as a tool to probe into an unknown biological process, it is termed as an exploratory model. When used to explain a hypothesis, animals are classified as explanatory models and when efficacy and safety of a drug or device are predicted using outcomes from animals, they are termed as predictive models. Based on the methodology followed to produce the models, animal models are classified as naïve or induced. In naive models, there can be spontaneous disease models that are mutants, and when selectively bred, become valuable tools for translational research. Induced models are created using a wide array of techniques starting from pharmacologic/chemical induced diseases, nutritionally induced diseases, surgical interventions, or molecular techniques like CRISPR-Cas9 giving birth to transgenics and knockouts. The basic and advanced concepts and approaches used in applied laboratory animal science to develop and validate animal models will be focused upon in this chapter.