Congenital central nervous system malformations in piedmontese calves-part 1. structural brain disorders.

INTRODUCTION

Congenital central nervous system (CNS) malformations in cattle are likely underreported, and their true incidence, clinical spectrum, and etiological factors remain poorly characterized. This study describes the clinical and pathological features of congenital structural brain anomalies in Piedmontese calves.

METHODS

In this prospective observational study (2021-2025), Piedmontese calves with suspected congenital CNS anomalies underwent clinical and neurological examinations, cerebrospinal fluid analysis, diagnostic imaging (CT/MRI in selected cases), molecular testing for regionally relevant teratogenic viral pathogens, and histopathology. The study population originated from the provinces of Cuneo and Turin (Italy), which together account for over 80% of Piedmontese cattle farms. Only calves with necropsy-confirmed structural brain anomalies were included.

RESULTS

In total, 70 calves underwent necropsy for suspected CNS anomalies. Structural brain defects were confirmed in 11 calves. Hydrocephalus (6/11) was the most frequent finding and was commonly associated with cerebellar malformations. Isolated Dandy-Walker-like malformations were found in 2/11 and cerebral aplasia in 3/11. Molecular testing for bovine viral diarrhea virus, bluetongue virus, and Schmallenberg virus was negative in all cases. A severe medullary dysplastic anomaly was also observed.

DISCUSSION: There was wide variability in the presentation of brain malformations in this sample of Piedmontese calves, in which the most common was hydrocephalus associated with cerebellar malformations. Since a viral etiology appeared unlikely, a genetic cause is suspected, and genomic analyses are currently ongoing to further investigate this hypothesis. These findings highlight the importance of considering congenital CNS malformations in the differential diagnosis of neurological disorders in neonatal calves, supporting earlier and more targeted diagnosis.