Aventriculi associated with holoprosencephaly in a dog

Area of Science:

• Veterinary Neurology
• Comparative Pathology
• Developmental Neurobiology

Background:

• Holoprosencephaly (HPE) is a rare congenital brain malformation.
• Aventriculi, the absence of brain ventricles, is an extreme manifestation of HPE.
• This condition has been documented in humans but is exceptionally rare in veterinary medicine.

Observation:

• A 10-month-old dog presented with poorly controlled seizures.
• Brain MRI revealed a complete absence of the lateral and third ventricles and mesencephalic aqueduct.
• Postmortem imaging confirmed the lack of a contiguous ventricular system.

Findings:

• Histopathology identified vestigial ventricles and hypoplastic choroid plexus.
• Atresia of the third ventricle and fused thalami were noted.
• Diagnosis was consistent with lobar holoprosencephaly (HPE).

Implications:

• This is the first reported case of radiographically confirmed aventriculi associated with HPE in veterinary literature.
• Highlights the importance of advanced imaging and histopathology for diagnosing rare congenital brain anomalies in animals.
• Contributes to comparative neurology by documenting a severe form of HPE in a canine patient.