Bilateral external jugular vein anomalies preventing hemodialysis catheter placement in a cat with anuria secondary to Lilium species intoxication.

Case series summary: A 2-year-old female spayed Abyssinian cat was evaluated for lethargy and inappetence that first occurred approximately 4 days prior. In addition, urination had not been observed by the owner for 5 days. A Lilium species plant had been brought into the house approximately 5 days before initial evaluation, and intoxication was therefore suspected. Bloodwork revealed anemia, severe azotemia and hyperkalemia. As the cat was anuric with severe azotemia, hyperkalemia and fluid overload, intermittent hemodialysis was recommended. Attempts were made to place a hemodialysis catheter into the external jugular veins bilaterally, but after initial successful venipuncture, the instrumentation would not pass into either vein. During fluoroscopic angiography, no internal jugular veins or external jugular veins caudal to the thoracic inlet were visualized and venous drainage from the head occurred via the vertebral veins. Owing to the anomalous anatomy in the cervical region, a hemodialysis catheter could not be placed into either jugular vein. Alternative sites for the placement of an extracorporeal catheter were discussed with the owner, but humane euthanasia was elected.

Relevance and novel information: To the authors' knowledge, this is the first report of a cat with bilateral external jugular vein anomalies resulting in blind endings that did not communicate with the vena cava. This was discovered during attempts to place a hemodialysis catheter for the management of anuric renal failure secondary to Lilium species intoxication. While this anatomical variation is likely uncommon, it is an important differential to consider when faced with challenging external jugular vein catheterizations in feline patients.