Meningoencephalitis of unknown etiology (MUE) is a common inflammatory central nervous system disease in dogs and is associated with a poor prognosis. The first 3 months post-diagnosis represent a critical prognostic window, as most mortalities occur within this period. The hemoglobin, albumin, lymphocyte, and platelet (HALP) score has emerged as a novel prognostic tool for predicting short-term mortality in various human diseases. However, its utility has not yet been evaluated in dogs with MUE