Modified Manual Therapeutic Plasma Exchange Technique as a Successful Treatment for Postattenuation Neurological Signs (PANS) in a Dog

OBJECTIVE: To investigate and describe the therapeutic potential of manual plasma exchange for controlling seizures and neurologic dysfunction in a dog with postattenuation neurologic signs (PANS). CASE SUMMARY: A 4-year-old neutered female Yorkshire Terrier was initially diagnosed using computed tomography with a congenital extrahepatic portosystemic shunt involving the left gastric and azygos veins. After diagnosis, surgical correction of the anomaly was performed without complications, and the patient was discharged. However, within 48 h of surgery, the dog developed a neurologic condition characterized by generalized tonic-clonic seizures that were poorly responsive to medical treatment. Given the timing and progression of clinical signs despite medical therapy, and after ruling out hepatic encephalopathy as a likely cause, a presumptive diagnosis of PANS was established. A modified, manual therapeutic plasma exchange (MTPE) technique was successfully performed over an 8-h period with minimal complications. After the procedure, marked clinical improvement was observed, with resolution of neurologic signs, and the patient was discharged without further procedure-related complications. NEW OR UNIQUE INFORMATION PROVIDED: PANS has been described in veterinary medicine in both dogs and cats, although its etiology and treatment remain poorly understood. This report describes the use of MTPE as a therapeutic approach, yielding promising results. To the authors' knowledge, this is the first documented use of MTPE for this condition in dogs, with previous reports limited to a single case in a cat.