Acute Hyperammonemic Encephalopathy after L-Asparaginase in a dog.

Publication date 1st December 2011
Authors Lyles SE, Kow K, Milner RJ, Buckley G, Bandt C, Baxter K


To describe a previously unreported and potentially fatal complication of L-asparaginase (L-asp) administration in a dog.



Clinical relevance

The purpose of this report is to describe the development of severe hyperammonemia after L-asp therapy in a dog, which has not been previously reported in the literature. Given the rapid progression and fatal outcome observed in this case, early recogniti


A 7-year-old, 6.6 kg, female spayed Beagle presented with a 1-week history of progressive inappetance and lethargy. Diagnostic tests identified the presence of stage Vb lymphoma and liver dysfunction. The dog was treated with L-asp at 400 IU/kg, corticosteroids, and IV fluids. Within 12 hours the dog became depressed, vomited, and developed abdominal pain. Within 24 hours, the dog's mentation progressed from obtunded to comatose; subsequently the dog developed a “decerebrate posture.” Blood ammonia concentrations exceeded 1,000 μmol/L (1,700 μg/dL). Treatment with broad-spectrum antimicrobials, lactulose enemas, and continuous renal replacement therapy were initiated without response and the dog suffered cardiopulmonary arrest.