Prognostic factors for 1-week survival in dogs diagnosed with meningoencephalitis of unknown aetiology

•This retrospective records study investigated 116 dogs diagnosed with meningoencephalitis of unknown aetiology (MUA).•Thirty of 114 (26%) of dogs died within 1 week of diagnosis of MUA.•Negative prognostic factors were decreased mentation and seizures at presentation.•An increased neutrophil percentage in CSF was also a negative prognostic factor.

Although long-term outcomes of meningoencephalitis of unknown aetiology (MUA) in dogs have been evaluated, little is known about short-term survival and initial response to therapy. The aim of this study was to evaluate possible prognostic factors for 7-day survival after diagnosis of MUA in dogs. Medical records were reviewed for dogs diagnosed with MUA between 2006 and 2015. Previously described inclusion criteria were used, as well as 7-day survival data for all dogs. A poor outcome was defined as death within 1 week. Of 116 dogs that met inclusion criteria, 30 (26%) died within 7 days of diagnosis. Assessed variables included age, sex, bodyweight, duration of clinical signs and treatment prior to diagnosis, venous blood glucose and lactate levels, white blood cell count on complete blood count, total nucleated cell count/total protein concentration/white blood cell differentiation on cerebrospinal fluid (CSF) analysis, presence of seizures and cluster seizures, mentation at presentation, neuroanatomical localisation, imaging findings and treatment after diagnosis. Multivariate analysis identified three variables significantly associated with poor outcome; decreased mentation at presentation, presence of seizures, and increased percentage of neutrophils on CSF analysis. Despite initiation of appropriate treatment, more than a quarter of dogs died within 1 week of diagnosis of MUA, emphasising the need for evaluation of short-term prognostic factors. Information from this study could aid clinical staff to provide owners of affected dogs with prognostic information.