Imaging diagnosis: Disseminated hemangiosarcoma in a Welsh pony

Area of Science:

• Veterinary Neurology
• Equine Oncology
• Diagnostic Imaging

Background:

• Epistaxis and head tilt in a pony were initially suspected to be an ethmoid hematoma.
• Neurologic abnormalities prompted further investigation beyond initial radiographic findings.

Purpose of the Study:

• To characterize the extent and nature of sinonasal, intracranial, and vertebral masses in a pony.
• To determine the underlying cause of severe neurologic deficits and epistaxis.

Main Methods:

• Contrast-enhanced computed tomography (CT) of the head and cranial neck.
• Postmortem examination for histopathological confirmation.

Main Results:

• CT revealed multiple hyperattenuating masses in the brain, paranasal sinuses, and a destructive vertebral mass causing myelopathy.
• Postmortem findings confirmed disseminated hemangiosarcoma involving sinonasal, intracranial, vertebral, and thoracoabdominal regions.
• Findings were inconsistent with ethmoid hematoma, with hemangiosarcoma being the primary diagnosis.

Conclusions:

• Disseminated hemangiosarcoma is a rare but significant cause of complex clinical signs in horses.
• Contrast-enhanced CT is invaluable for assessing the severity and regional involvement of such neoplastic diseases.
• Advanced imaging directly influences diagnostic and management decisions in complex equine cases.