There are a wide variety of substances poisonous to dogs. Many pet owners have a general knowledge of dog health, but not of the larger scope of common substances poisonous to dogs. Recognizing the signs of poisoning will enable dog owners to get the help their dogs need when exposed to poisons. Dogs can be exposed to poisons in several ways: ingestion, contact, and inhalation. The most common poisonous substances include some human foods and medications, household products, and many plants. Understanding exposure and symptoms of poisoning and poisonous substances will assist dog owners in identifying how to get the correct treatment for their pet.