Overdosing happens when a safe substance is given in excess, while toxicity happens due to unsafe substances even if given in minimal doses to dogs. In more practical terms, what dog owners should know is that CBD can cause an overdose while THC toxicity. Let's take a closer look into the difference between overdose and toxicity.  An overdose occurs when a dog is given more than the recommended amount of some otherwise safe and beneficial medication, supplement, or natural substance. In such a case, the pet's metabolism cannot detoxify the substance fast enough, causing unintended side effects. Pet poisoning or toxicity is different from an overdose. Toxicity occurs when a dog ingests a drug that has no benefit in any dose but holds toxic potential. This poison could be a human medication, a plant in your home, marijuana products, wild mushrooms, or more.