A case of cranium bifidum with meningocele in Ayrshire calf

Abstract

BackgroundCongenital cranial bone defects predispose to herniation of meninges, sometimes with brain tissue involvement, to form a cerebrospinal fluid (CSF)–filled cyst in the head. Such defects mainly results from focal failure of neural tube closure during fetal development and has been reported in various species of domestic mammals.Case presentationA one week old Ayrshire calf with a fluctuant swelling on parieto-occipital region of the head was referred to the faculty. The calf was always lying on lateral recumbency and exhibited resistance to deep palpation around the swelling and neck flexion. Embedded to the midline of the dorso-caudal surface of the cyst’s wall was a hard longitudinally oriented structure. The case was diagnosed as meningocele by means of radiographic examination. As the likelihood to full recovery was greatly reduced due to the negative impact already meted on brain tissue by intracranial pressure, the calf was euthanized on grounds of animal welfare and the diagnosis confirmed by anatomopathological findings which also revealed a circular bone defect in parieto-occipital region of the skull vault and a flattened bony structure embedded to the cyst’s wall.ConclusionAnatomopathological findings confirmed the diagnosis as cranial bifidum with meningocele at the parieto-occipital region of the skull vault. The presence of a bony structure embedded to the wall of meningeal sac was rather unusual and could not be sufficiently explained. It was however thought to, most likely, represent a part of interparietal bone that failed to get incorporated into squamous part of occipital bone as a result of the defect. The report also highlights challenges that work against timely delivery of urgent veterinary interventions in rural set ups of Africa and rest of the developing world, often leaving veterinarians with animal welfare consideration as main determinant of intervention measures.

Long-term pedigree analysis: An effective tool for managing congenital malformations in cattle

“…According to Rolo et al (2019), the defect does not likely occur because of faulty closing of the neural tube; rather, it is likely caused by later damage to superficial ectodermal structures of the already closed neural tube. As reported by Kisipan et al (2016), such congenital defects of the skull also occur in other mammals, including horses, pigs and humans.…”

“…Cranial meningocele (containing only the meninx) has been well documented in the Ayrshire calf, and cranioschisis with meningocele has been well documented in the Shorthorn calf and is associated with additional anomalies, including tibial hemimelia and abdominal hernia. The Shorthorn calf is a member of a group of related calves that present tibial hemimelia and other defects (Lapointe et al 2000;Kisipan et al 2016).…”