Systemic mastocytosis leading to anaphylaxis in an adult cat

A 14‐year‐old, male, neutered domestic shorthair cat presented for evaluation of an acute episode of vomiting and collapse. The cat presented with severe cardiovascular instability that was unresponsive to intravenous fluid boluses. The cat subsequently underwent cardiopulmonary arrest, and cardiopulmonary resuscitation was unsuccessful. A postmortem examination revealed systemic mastocytosis as well as an incidental finding of lymphoma in the jejunum. This case report highlights the first report and clinical presentation of anaphylaxis in a cat with systemic mastocytosis, as well as recommendations for treating anaphylaxis in cats.