Case Report: Therapeutic plasma exchange for systemic centipede envenomation in a 2-kg Chihuahua dog

A 2-kg, 8-year-old neutered male Chihuahua was presented after a centipede sting to the interdigital region of the right forepaw, followed by lameness and red urine. Wound care and intravenous fluid therapy were provided at the referring clinic; however, pigmenturia persisted and systemic manifestations developed, prompting referral. On admission, the dog had icteric mucous membranes, mild dehydration, and clinicopathologic evidence of systemic inflammation, tissue injury, hepatocellular damage, and suspected hemolysis. Because of the acute systemic manifestations following envenomation and persistence of clinical abnormalities despite initial medical management, membrane-based therapeutic plasma exchange (TPE) was performed. Estimated plasma volume was 96 mL, and the prescribed exchange volume was 134 mL (1.4 plasma volumes). Approximately 1,080 mL of whole blood was processed over 3 h. The 68-mL extracorporeal circuit was primed with whole blood, anticoagulation was achieved with heparin, and fresh frozen canine plasma was used as the replacement fluid. TPE was completed over 3 h at a whole blood flow rate of 6 mL/min; transient asymptomatic ionized hypocalcemia was detected and treated with calcium gluconate. After treatment, C-reactive protein decreased from 8.9 to 1.5 mg/dL and appetite returned, although depression initially persisted. The dog subsequently improved during hospitalization and was discharged after 7 days. In this dog, membrane-based TPE was well tolerated despite the small body size and was temporally associated with improvement in clinical signs.