Postanesthetic neurologic signs progressing to seizures in 2 dogs and 1 cat with unoperated congenital portosystemic shunts after non-shunt-related surgery.

Objective: To describe the development of neurologic signs progressing to seizures in 2 dogs and 1 cat with unoperated single congenital portosystemic shunts (CPSSs) after general anesthesia for non-shunt-related surgery and no intraoperative shunt manipulation.

Animals: 2 dogs (dog 1 [a 5-year-old 7.1-kg castrated male Bichon Frise] and dog 2 [a 10-year-old 7.3-kg castrated male Bichon Frise]) and 1 cat (cat 1 [a 2-year-old 3.8-kg castrated male Ragdoll]).

Clinical Presentation: Medical records from the University College Dublin Veterinary Hospital and Royal Veterinary College Queen Mother Animal Hospital were searched for dogs and cats with unoperated CPSSs that developed neurologic signs progressing to seizures after general anesthesia for non-shunt-related surgery between January 1, 2015, and June 31, 2024.

Results: 3 animals were identified. Dogs 1 and 2 both underwent cholecystectomy, whereas cat 1 underwent jejunal enterectomy. None had known preoperative seizures, although both dogs had experienced prolonged anesthetic recovery after previous surgery and the cat had a 3-day history of ataxia, walking into walls, and generalized weakness. All 3 animals developed severe neurologic signs including seizures within 48 hours postoperatively. Both dogs were euthanized before hospital discharge: dog 1 for suspected aspiration pneumonia coupled with severe neurologic signs and dog 2 for refractory neurologic signs. Cat 1 survived to hospital discharge and underwent 2 subsequent CPSS attenuation surgeries.

Clinical Relevance: Postanesthetic neurologic signs can occur in animals with CPSSs without intraoperative shunt manipulation. This possible complication should be discussed with owners of animals with unoperated CPSSs that require general anesthesia for non-shunt-related surgery.