Abstract

Hydrocephalus is an accumulation of cerebrospinal fluid within the cranial ventricle which has been observed in several companion animal species. The clinical consequence of this condition can cause neurological disorders including seizures, abnormal head position, and behavioral changes. However, these presenting signs in aquatic reptilian species, such as sea turtles, are difficult to observe due to habitat, anatomical differences, and difficulty of neurological examination.

The stranded juvenile green sea turtle was rescued from Laem-Singha Estuarine at Chantaburi province. The turtle was mildly emaciated (2/5 body condition score), floating and intermittent anxiety. Neurological examination revealed left-sided head turn, bilateral circling, and seizure-like appearance. The turtle was sent to referral veterinary hospital to investigate the cause of stranding by serum chemistry, serum heavy metal contamination analysis, radiography, endoscopy, computed tomography (CT-scan), and magnetic resonance imaging (MRI). MRI illustrated dilatation of cranial ventricle and central canal, indicating hydrocephalus and cervical syringomyelia, and low signal focal area under cerebral hemisphere. After 2 weeks of treatment, the turtle died, and the carcass was sent for necropsy. Necropsy demonstrated frothy exudate in trachea towards bronchioles and firm mass in cranial ventricle. Histopathological figures displayed diffusely multifocal cerebral vasculitis, granulomatous meningitis, encephalopathy, and obstructive hydrocephalus. Lung had diffuse vasculitis with marked eosinophilic cellular debris and multifocal lymphoid aggregation. Kidney had diffuse vasculitis, diffuse tubulonecrosis, and multifocal interstitial fibrosis.

In conclusion, the primary cause of hydrocephalus was originally by generalized vasculitis which lead to secondary bacterial infection resulting in granulomatous inflammation within the cranial ventricle. The granulomatous mass caused an obstruction of CSF flow and an increase in intracranial pressure which resulted in brain compression and neurological deficits.

* Presenting author, + Student presenter