Computed Tomography of Coenurus cerebralis in Sheep: High Diagnostic Sensitivity With Limited Association to Clinical Severity.

BACKGROUND AND AIMS: Coenurosis is an important cause of neurological disease in sheep in endemic regions. Ante-mortem diagnosis is primarily based on clinical signs, which are often nonspecific. Computed tomography (CT) can detect intracranial cystic lesions. This study aimed to describe CT imaging features of Coenurus cerebralis in sheep and to evaluate their association with neurological clinical findings. METHODS: Twenty 7-month-old Afshari male lambs with neurological signs consistent with coenurosis and 20 healthy matched controls were included. Affected animals underwent neurological examination, clinical severity scoring, and cranial CT imaging using a standardized protocol. Cyst number, volume, and anatomical location were recorded, and Hounsfield unit (HU) values of cyst fluid, brain parenchyma, and skull bone were measured. Diagnosis was confirmed by gross pathological examination and PCR targeting the mitochondrial COX1 gene. Associations between CT variables and clinical findings were analyzed using regression models. RESULTS: All cysts identified at necropsy were detected by CT, corresponding to a sensitivity of 100%. No significant associations were found between cyst number, size, or location and neurological signs or clinical severity score (p > 0.05). HU values of brain parenchyma and cranial bone were significantly lower in affected sheep compared with controls (p < 0.001). CONCLUSION: CT is highly sensitive for detecting cerebral cysts in sheep with coenurosis. However, CT-derived structural features are not associated with clinical severity and should not be used for prognostic evaluation. CT remains a valuable adjunct diagnostic tool when interpreted alongside clinical findings.