Retrospective Evaluation of the Indications, Complications, and Outcomes of Extracorporeal Therapies in Companion Animals in a Veterinary Teaching Hospital.

OBJECTIVE: To decribe the indications, complications, and outcomes of companion animals treated with extracorporeal therapy (ECT). DESIGN: Retrospective case series from November 2023 to December 2024, with a 1-month follow-up. SETTING: Single-center study at a veterinary university teaching hospital. ANIMALS: Forty-one client-owned animals (37 dogs, four cats) treated with ECT for endogenous substance accumulation (ESA [n = 28], including acute kidney injury [AKI; n = 27] or post-attenuation neurologic signs [PANS; n = 1]), immune-mediated disease (IMD; n = 3), or intoxication (n = 10). MEASUREMENTS AND MAIN RESULTS: Data collected included signalment, indication, ECT type (hemodialysis [HD], hemoperfusion [HP], or therapeutic plasma exchange [TPE]), complications, and outcome. A total of 103 ECT sessions were performed. Session complications were frequent (HD: 27%, HP: 71%, TPE: 64%), most commonly circuit clotting (15/103), hypocalcemia (10/103), bleeding (9/103), and hemodynamic instability (9/103); none were fatal. Assessment of specific complication risks by ECT type was limited by sample size, but the complication rate of HD was lower compared with other modalities (p = 0.012). Overall, 25 of 41 animals were discharged, and 20 of 25 survived 1 month. Survival in dogs differed by indication: 100% (10/10) for intoxication, 57% (13/23) for AKI, and 33% (1/3) for IMD (p = 0.006). Among dogs with AKI, those with probable or confirmed leptospirosis had higher 1-month survival (9/19) compared with other causes of AKI (1/4) (p = 0.014). CONCLUSIONS: ECT is associated with a moderate to high complication rate, but most complications were mild and transient. Intoxicated patients receiving ECT had an excellent prognosis, while dogs with AKI and confirmed or probable leptospirosis showed better survival than those dogs with AKI unlikely to be due to leptospirosis.