Owners are often not aware that some common household products, medications, and plants are toxic to dogs and cats. Six cases of toxicoses due to ingestion of xylitol, amatoxin-containing mushrooms, anticoagulant rodenticide, zinc, vitamin D, and lily are presented with typical clinical and laboratory data findings. Changes in the laboratory data are explained in the context of the mechanism of action of the toxin and the organ systems affected.