Marijuana (Cannabis sativa) is a commonly used recreational drug among humans; animals may be exposed following ingestion or accidental inhalation of smoke. From January 1998 to January 2002, 213 incidences were recorded of dogs that developed clinical signs following oral exposure to marijuana, with 99% having neurologic signs, and 30% exhibiting gastrointestional signs. The marijuana ingested ranged from 1/2 to 90 g. The lowest dose at which signs occurred was 84.7 mg/kg and the highest reported dose was 26.8 g/kg. Onset of signs ranged from 5 min to 96 h, with most signs occurring within 1 to 3 h after ingestion. The signs lasted from 30 min to 96 h. Management consisted of decontamination, sedation (with diazepam as drug of choice), fluid therapy, thermoregulation and general supportive care. All followed animals made full recoveries.