Sudden death in rabbits can be caused by a variety of factors, such as infections, trauma, toxins, or heart problems. Infections such as pasteurellosis and myxomatosis can cause sudden death in rabbits due to the bacterial toxins they produce. Trauma from falls or being stepped on can also lead to sudden death if the rabbit sustains major internal injuries that cannot be repaired. Toxins like antifreeze and other chemicals are poisonous to rabbits and exposure can lead to sudden death. Heart issues such as cardiomyopathy are another possible cause of sudden death in rabbits; this is when the heart becomes enlarged and has difficulty pumping blood throughout the body.