Cannabis Toxicity

Cannabis toxicity occurs when a dog or cat ingests material containing THC (tetrahydrocannabinol), the psychoactive compound found in marijuana plants, edibles, oils, or discarded cannabis products. The substance affects the nervous system in ways that can produce a distinctive set of signs, though the severity and pattern vary depending on the dose, the form ingested, and the individual animal. Owners most commonly notice a sudden change in behaviour and coordination—pets may appear unusually drowsy or unsteady, may dribble urine, or may startle easily at sounds or touch. Some animals become very still and seem disoriented, while others may twitch or show repetitive movements. The signs often develop within an hour or two of ingestion, though edibles containing fats can delay onset. Many owners arrive at this page uncertain whether what they are seeing fits a known pattern, or whether cannabis could explain what they are observing. This page explores the signs that can appear, what THC does in the body to produce those effects, how the condition is investigated when the history is unclear, and the range of approaches used to support affected animals while the compound clears. The focus is on helping you understand the shape of the problem and the logic behind how it is typically managed.