Canine vertebral venous thrombosis: confirmatory MRA before retreatment following symptom recurrence

Venous thrombosis within the internal vertebral venous plexus is a rare occurrence in both human and veterinary medicine. This case report details the evaluation and management of an 18-month-old female spayed Siberian Husky Mix diagnosed with internal vertebral venous plexus thrombosis after presenting with cervical pain and mild tetraparesis. Initial imaging using magnetic resonance imaging (MRI) revealed asymmetric enlargement of the right internal vertebral venous plexus without evidence of spinal cord compression. Cerebrospinal fluid analysis was unremarkable. The dog was treated with clopidogrel and analgesics, leading to significant clinical improvement. However, clinical signs recurred after 20 weeks, prompting a repeat MRI that confirmed persistent thrombus. The treatment regimen was reinitiated, resulting in resolution of clinical signs. This case underscores the need for specific guidelines regarding the diagnosis and management of venous thrombosis in veterinary patients, as current literature predominantly references human medicine. The report also highlights the potential role of advanced imaging techniques, such as phase-contrast magnetic resonance angiography (MRA), in diagnosing vascular conditions in veterinary practice.