acute myocarditis was induced in experimental dogs by subcutaneous (sc) injection of 3mg/kg of scorpion venom from mesobuthus tamulus concanesis pocock (earlier called buthus tamulus). an increase in hemoglobin (hb), mean corpuscular hemoglobin concentration (mchc), packed cell volume (pcv), plasma hemoglobin (plasma hb) levels, and increased osmotic fragility of erythrocytes in vivo was observed after envenoming. an increase in osmotic fragility of red blood cells (rbc) was also observed when the blood in vitro was incubated with different concentrations of scorpion venom. species- specific scorpion antivenom (sav) was administered to different groups of animals at different time intervals following scorpion envenoming. this resulted in a decrease in hb, mchc, pcv, and plasma hb levels in the envenomed animals and reversal of osmotic fragility changes of erythrocytes. it has been suggested that scorpion venom causes an autonomic storm releasing massive amounts of counter-regulatory hormones, such as catecholamines, angiotensin-ii, glucagon, cortisol, and changes in insulin secretion resulting in hematological and osmotic fragility changes of erythrocytes. administration of sav effectively neutralized, prevented, and reversed scorpion venom toxicity and related osmotic fragility changes of erythrocytes.