There is a potential risk of getting sick from a dead mouse due to the diseases it may carry and the bacteria associated with decomposition. Some diseases that mice can transmit include hantavirus, leptospirosis, and salmonellosis. To minimize the risk of getting sick, it's important to handle a dead mouse with care, wearing gloves and using appropriate sanitation practices. If you come into contact with a dead mouse or its droppings, wash your hands thoroughly with soap and warm water. If you develop any symptoms after handling a dead mouse or suspect exposure to mouse-borne diseases, it's best to consult a healthcare professional for advice and guidance.