Cat with severe anemia and Heinz bodies after eating onion

Abstract

Abstract Onion ingestion has been documented to induce hemolytic anemia in several species, including cats, following oxidative degeneration of hemoglobin and subsequent Heinz body (HB) formation. The presence of ghost cells on peripheral blood smears suggests recent intravascular hemolysis. The present case report aimed to describe a case of hemolytic anemia in a client-owned 5-year-old male neutered domestic shorthair cat following onion consumption with the occurrence of large ghost cells with Heinz body inclusions. On presentation, the cat had a recent history of weakness, diarrhea, and pigmenturia. The physical findings included pale mucous membranes, tachycardia with IV-grade heart murmur, and low body temperature (36.6 °C). Diagnostic investigations showed moderate microcytic hyperchromic anemia with mild regeneration and a large percentage of ghost cells with large HBs observed on microscopic examination of stained blood smears. These findings were supportive, along with the proof of onion ingestion, of hemolytic anemia associated with oxidative injury. The cat was euthanized following the diagnosis due to severe prognosis and to the financial constraint of the owner. Heinz bodies develop in case of oxidative injury of red blood cells, and during hemolytic anemia, lysed red blood cells can also be evident (ghost cells). This case report suggests that onion ingestion can lead to anemia with more severe erythrocyte alterations such as ghost cells with remarkably large HBs, which have not been previously described in feline onion ingestion.