Central Nervous System Diseases in Cattle, Small Ruminants, and South American Camelids: A Retrospective Study.

Neurological disorders in ruminants and South American Camelids (SACs) are rare, yet they constitute a clinically significant group owing to the complexity of their diagnosis and management. This retrospective study evaluated the prevalence, aetiologies, and clinical characteristics of central nervous system (CNS) diseases in cattle, small ruminants, and SACs admitted to the University Clinic for Ruminants in Vienna between 1992 and 2021. Medical records were reviewed, and cases were included if neurological clinical signs were documented at initial examination and/or a disorder of the CNS was confirmed as the final diagnosis. Data were analysed with respect to species, age, sex, season of presentation, and clinical outcome, with post-mortem findings evaluated where available. Descriptive statistics and chi-square tests with a significance level of p<0.05 were applied. Of 21,436 patients reviewed, 508 animals met the inclusion criteria, and post-mortem examination was available in 64.2%. CNS disorders were most frequently observed in small ruminants, whereas lower proportions were observed in SACs and cattle. Inflammatory and metabolic-toxic conditions predominated, particularly in animals younger than two years. A significant seasonal pattern was identified in ruminants, with most cases presenting during winter and spring. Survival rates varied across species. These findings demonstrate that CNS diseases are associated with considerable morbidity and mortality, highlighting the continued importance of early recognition, preventive management strategies, and post-mortem examination for definitive diagnosis.