Hemolytic anemia, spherocytosis, and thrombocytopenia associated with honey bee envenomation in a dog

Abstract

This case report describes a massive honey bee envenomation in a 14-month-old male Belgian Malinois dog from St. Kitts, West Indies. Acute and delayed onsets of hemolytic anemia, echinocytosis, spherocytosis, thrombocytopenia, hemoglobinemia, and hemoglobinuria developed following envenomation. The dog recovered after treatment with glucocorticoids and supportive therapy. Spherocytosis, hemolysis, and thrombocytopenia in patients with massive bee envenomation are likely due to the direct toxic effects of the primary components of bee venom, melittin and phospholipase A₂ (PLA₂ ). Mellitin causes hemolysis by forming large pores in erythrocytes resulting in leakage of hemoglobin and also causes spectrin stiffening and resultant echinocyte and spherocyte formation. Melittin also stimulates PLA₂ , a hydrolase that causes echinocytosis and spherocytosis, in vivo and in vitro, and mitochondrial breakdown in platelets. However, delayed manifestations could be attributed to immune-mediated mechanisms from the generation of antibodies against damaged erythrocytes and platelet membrane proteins.

Keywords: bee venom; melittin; phospholipase A2.