Development of a psychobiological nosology for fear and frustration in clinical animal behavior using dogs as a model species.

Assessing emotion is an integral part of the diagnostic process in clinical animal behavior and facilitates more specific management for the related behavior. Fear and frustration are commonly involved in such issues, and clinical animal behaviorists appear to find these emotions challenging to identify and differentiate, with a range of views on the nature of these emotions. This problem is compounded by a lack of consensus definitions for these terms, authors frequently relying on intuitive understanding, and the variability in definitions used, when they are actually defined, within the clinical animal behavior literature. We therefore sought to critically appraise existing clinical animal behavior literature on fear and frustration, before proposing a more formal functional psychological and biological (psychobiological) framework, which was inspired by work describing the evolved function of disgust. Our proposed definitions for fear and frustration structure and unite existing theories across the biological and psychological sciences with prominent research in the clinical animal behavior field, to provide a consistent frame of reference (nosology) for future research and clinical practice. We have used dogs as a model species to highlight how existing clinical literature can be usefully aligned into evolutionary-relevant themes relating to ecological context and key cognitive capacities. The outcome has the potential to not only be practically useful, in helping to standardize the dialogue relating to these emotional states, but also the methodology used could be more widely applicable to help improve future scientific research on affect.