Most fertilizers contain varying amounts of nitrogen, phosphorus and potassium (potash). An organic fertilizer may also include plant and animal by-products, rock powders, seaweed, inoculants, and conditioners. They only become toxic in a warm, moist environment which is exactly what is inside your pet. While small ingestions of fertilizer may only result in mild stomach upset, larger ingestions can result in severe poisoning from the iron, nitrogen and other chemicals. Large ingestions of meal-based fertilizers may also form a concretion in the stomach resulting in a bowel obstruction or severe and painful inflammation of the pancreas (pancreatitis).
If you think your dog or cat was exposed to fertilizer, contact your veterinarian.