Received: 6 June 2017 Revised: 17 September 2017 Accepted: 7 November 2017 DOI: 10.1111/vec.12888 CASE REPORT Severe hypernatremia and transient azotemia in a cat following inadvertent intravenous administration of a commercial polyethylene glycol solution Sabrina N. Hoehne DVM, DACVECC, DECVECC 1 Casey J. Kohen DVM, DACVECC 1 Birgit Puschner BS, DVM, PhD, DABVT 3 Ingrid Gennity PhD 3 Simon P. Hagley BVSc 1 Kate S. Farrell DVM, DACVECC 1 Karin Unger DVM 1 Laura A. Cagle DVM 4 Karl E. Jandrey DVM, MA, DACVECC 2 1 William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, CA 2 Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 3 Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA 4 Center for Comparative Respiratory Biology and Medicine, University of California, Davis, CA Correspondence Dr. Sabrina N. Hoehne, Department of Veterinary Clinical Medicine, Division of Small Animal Emergency and Critical Care, Vetsuisse Faculty, University of Bern, Laenggassstrasse 128, 3012 Bern, Switzerland. Email: sabrina.hoehne@vetsuisse.unibe.ch Abstract Objective: To describe the clinical signs, clinicopathologic abnormalities, treatment, and outcome after IV administration of polyethylene glycol 3350 (PEG3350) in a cat. Case Summary: A cat was inadvertently administered 6 g/kg of PEG3350 in electrolyte solution, IV, resulting in severe hypernatremia (203 mmol/L), diffuse encephalopathy, hemolysis, and mod- erate azotemia. The hemolysis and acute kidney injury observed immediately following PEG3350 administration resolved with supportive care. Administration of IV and oral electrolyte-free water slowly corrected the hypernatremia and the neurologic signs subsequently improved. Complete resolution of clinical signs was documented one month following hospital discharge. The PEG3350 concentrations in serum, plasma, and urine samples confirmed toxic exposure to PEG3350. Effi- cacy of treatment was evident by decreasing concentrations of PEG3350 in serum after the first 24 hours of treatment. Renal elimination of PEG3350 was significant and PEG3350 was still detected in the urine 17 days after exposure. New Information Provided: This is the first report to describe the clinical signs and clinicopatho- logic abnormalities in a cat intoxicated with IV PEG3350. Potential pathophysiologic mechanisms are discussed, and the successful supportive medical treatment is outlined. KEYWORDS feline, intoxication, polyethylene glycol, sodium 1 CASE PRESENTATION An 11-year-old female neutered domestic shorthair cat was referred to the Small Animal Emergency Service of the William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis for acute neurologic signs and severe hypernatremia following inadvertent IV administration of polyethylene glycol 3350 (PEG3350) with electrolyte solution (PEG-ES) ∗ . Five days prior to the incident, the Abbreviations: 4-MP, 4-methyl-pyrazole; CUDA, 12-[[(cyclohexylamino)carbonyl]amino]-dodecanoic acid; EG, ethylene glycol; NE, nasoesophageal; PEG3350, polyethylene glycol 3350; PEG-ES, polyethylene glycol 3350 with electrolyte solution; RER, resting energy requirement. c  Veterinary Emergency and Critical Care Society 2019 patient was presented to the primary care veterinarian for a 1-week history of hyporexia, vomiting, tenesmus, decreased fecal production, and hematochezia. Significant physical examination findings included a weight of 4 kg, mild dehydration, II/VI left parasternal systolic heart murmur, and formed fecal material in the colon. CBC, urinalysis, fecal floatation, and serum biochemistry analyses were all within reference intervals (creatinine concentration 150 μmol/L [79 to 221 μmol/L]; 1.7 mg/dL [0.9 to 2.5 mg/dL], BUN concentration 9.3 mmol/L [5.7 to J Vet Emerg Crit Care. 2019;1–6. wileyonlinelibrary.com/journal/vec 1