One of the harmful consequences of the human use of illicit drugs is the unintentional exposure of pets. With the legalization of marijuana in some states, the reports of marijuana toxicity in pets has increased. A pet's exposure to marijuana can be deadly.

  • Marijuana is a psychoactive (mind-altering) drug derived from the Cannabis sativa plant. In humans it is used medicinally and recreationally and accounts for a small, but increasing, percentage of emergency department visits.
  • Its main chemical component, THC, is similar to a chemical in the brain called anandamide. This chemical works on a system that plays an important role in normal brain development and function including things like memory, thinking, pleasure, sensation, and coordination.
  • Also Known As: Mary Jane, Grass, Pot, Hashish, Reefer, Weed, Indian Hemp
  • Hemp is another cultivar or strain of the Cannabis sativa plant and is not considered toxic to pets as it is very low in THC

Marijuana is Poisonous to Dogs and Cats

  • The most common route of exposure in pets is by ingestion
  • Diagnosis is based on knowledge of exposure and typical clinical signs, which can be seen in dogs within 30 minutes of ingestion and can last as long as 2 to 3 days
  • Animals are sensitive to THC, which acts on cannabinoid receptors to induce central nervous system effects such as increased production of dopamine, norepinephrine and serotonin
  • Lethal dose for dogs is approximately 3 grams/kg

Clinical signs

  • Depression
  • Ataxia (wobbly gait)
  • Increased or decreased heart rate
  • Hypothermia (decreased body temperature) or hyperthermia (increased body temperature)
  • Increased vocalization
  • Increased salivation
  • Vomiting and/or diarrhea
  • Dilated pupils
  • Urinary incontinence
  • Tremors
  • Seizures, coma and/or death


  • Supportive care including intravenous fluids
  • Induced emesis (vomiting) and activated charcoal (for detoxification)
  • Stabilization of the central nervous system and heart rate
  • Anti-anxiety medications or sedatives if agitated
  • Body temperature regulation