Hemorrhage
Anticoagulants such as warfarin in rat poisons normally cause bleeding several days after ingestion. Visible bleeding may occur from the nose and gums and causes large bruises all over the body. Visible blood may be seen in the urine and stools and may also be vomited. Internal bleeding can cause pallor and low blood pressure. Bleeding can deplete red blood cells, causing anemia. Fatigue, shortness of breath, rapid heartbeat, dizziness, headache, and cold hands and feet can occur. Bleeding into the brain can cause confusion, agitation or lethargy.
Cardiopulmonary Effects
Zinc phosphide, still available in retail stores in the United States, according to the National Pesticide Information Center, can cause tightness in the chest, difficulty breathing and cough. Pulmonary edema, or fluid in the lungs, may develop. Cardiomyopathy, weakening of the heart muscles and irregular heartbeat can also occur with zinc phosphide poisoning.
Liver Failure
Ingestion of zinc phosphide can cause liver damage, with jaundice, a yellow discoloration of the skin and whites of the eyes and coma from encephalopathy, brain damage related to toxin buildup in the brain in liver failure.
Convulsions
Strychnine, a poison approved for used only by trained personnel, can cause severe convulsions, usually within 15 to 20 minutes after ingestion, the NPIC warns. Convulsions can also occur after zinc phosphide poisoning.
Shock
If internal bleeding continues, shock develops from decreased blood volume, or hypovolemia. Low blood pressure, difficulty breathing, apprehension, decreased urine output, sweating, low body temperature, kidney or brain damage and loss of consciousness. Coma and death can follow. Shock can also occur in zinc phosphide poisoning.