Novel Imaging Modalities for Antemortem Diagnosis of a Suspected Jugular Thrombus in a Bearded Dragon (Pogona vitticeps)

Abstract

A 5-year-old male central bearded dragon (Pogona vitticeps) presented with a three-day history of left forelimb lameness, minimal muscle tone, and absent pain sensation distal to the mid-humerus. Computed tomography (CT) revealed thickened and hypoattenuating soft tissues adjacent to the left scapulohumeral and left neck regions with no abnormal contrast enhancement. The suspected left external jugular vein in this region was ill-defined and small, with filling defects, consistent with the appearance of a venous thrombus. Focal ultrasound of the left side of the neck confirmed a thrombus in this location, just cranial to a jugular venous valve. The patient was treated with supportive care and started on clopidogrel as an antithrombotic treatment. Clinical improvement was minimal following this visit and the patient presented again five months later after declining significantly. On follow-up imaging at this visit, a suspected cardiac mass was seen on echocardiography. A fine-needle aspirate of the mass at that time was suspicious for a sarcoma, however the sample was non-diagnostic. The previously identified thrombus could not be detected on ultrasonography at this visit. The owner ultimately decided to pursue hospice care at home and no additional imaging or further workup was performed. This is the first report in reptiles describing a venous thrombus using diagnostic imaging. Given the reported occurrence of aneurysms and thrombi in bearded dragons in clinical practice, this case demonstrates the use of an important tool for diagnosis of these conditions.