Introduction
Cannabis refers to the psychoactive substances drawn from the dried leaves and flowers of the plant Cannabis sativa, the active ingredient being tetrahydrocannabinol (THC). The synonyms for the leisure drug include weed, pot, dope, grass, marijuana and hashish. Pets are at risk of cannabis intoxication if they eat cannabis or inhale the smoke
What is cannabis poisoning in pets?
This is the accidental ingestion (or inhalation) of cannabis containing tetrahydrocannabinol (THC), which is the principal active ingredient, from the plant Cannabis sativa - usually found in the form of cannabis/marijuana (dried leaves and flowers of the plant) or hashish (dried resin from flower tips).
What are the presenting signs of cannabis poisoning?
Cannabis poisoning effects occur rapidly (within 30-60 minutes). The effects, however, occur quicker if cannabis is ingested with fatty foods such as cake. But if inhaled, the signs and effects of cannabis may be delayed to about 4 hours after exposure. The effects include:
Collapse
Wobbliness, incoordination when walking or taking really long steps
Slow or fast heart rate, fast breathing
Weakness
Dilated pupils and reddened eyes
Salivation and vomiting
Drowsiness and depression, disorientation
Behavioural changes with aggression, agitation, vocalising and apparent hallucinations
Low or high body temperature
Urinary and faecal incontinence
Twitching, tremors or seizures
How is the rate of occurrence in society?
The increased acceptance of cannabis use in society has increased the incidence of its poisoning in dogs. The poisoning occurs when dogs accidentally ingest homemade biscuits or cakes containing cannabis, e.g., cannabis cookies, cannabis cake, the ends of cannabis cigarettes or the deliberate supply of cannabis or hashish by the owner. Cannabis poisoning has sporadically been reported in 'sniffer' dogs that happen to ingested their findings.
How is the risk of cannabis poisoning prevented in pets?
Cannabis products should be stored out of sight and out of reach of pets and cannabis-containing baked goods (eg cannabis cookies or brownies) should not be left where pets can access them.
Pets should not be fed cannabis nor do owners smoke cannabis around their pets. Smokers should make sure that the area is well ventilated before allowing pets back in.
What needs to be done if a pet is suspected to have eaten cannabis?
First, the pet needs to be removed from the source of poisoning, and any suspect material from the dog’s mouth.
A sample of what has been eaten or a sample of the vomit (DO NOT attempt to make the pet vomit) should be collected.
A vet needs to be contacted immediately for advice and or the pet and the suspect material taken to the veterinary clinic.
What is the Treatment of cannabis poisoning?
1. Absorbents (activated charcoal), are administered repeatedly as THC recirculates between the liver and the intestines.
2. Supportive therapy (intravenous fluids if the dog shows signs of hypotension, and keeping the dog warm, quiet and in a dark environment).
3. If the dog is excessively agitated or excited, sedation with diazepam is done.
4. If there is severe respiratory depression, assisted ventilation may be necessary.
Animals can recover within 24 hours if only mildly affected but in those with more pronounced effects, recovery may take 3-4 days. When treated, the prognosis is good.
References
Fitzgerald, K. T., Bronstein, A. C., & Newquist, K. L. (2013). Marijuana poisoning. Topics in companion animal medicine, 28(1), 8-12. PubMed.
Meola, S. D., Tearney, C. C., Haas, S. A., Hackett, T. B., & Mazzaferro, E. M. (2012). Evaluation of trends in marijuana toxicosis in dogs living in a state with legalized medical marijuana: 125 dogs (2005–2010). Journal of Veterinary Emergency and Critical Care, 22(6), 690-696.PubMed.
Janczyk, P., Donaldson, C. W., & Gwaltney, S. (2004). Two hundred and thirteen cases of marijuana toxicoses in dogs. Veterinary and human toxicology, 46(1), 19-20.PubMed.
McKnight, K. (2003). Marijuana toxicosis. Veterinary Technician 24 (4), 264-266 ASPCA Pro.
Donaldson, C. W. (2002). Marijuana exposure in animals. Vet Med, 97(6), 437-439.
Valentine, J. (1992). Unusual poisoning in a dog. The Veterinary Record, 130(14), 307. PubMed.
Godwin R L (1992) Unusual poisoning in a dog. The Veterinary Record 130 (15), 335-336 PubMed.
Dumonceaux, G. A., & Beasley, V. R. (1990). Emergency treatments for police dogs used for illicit drug detection. J Am Vet Med Assoc, 197(2), 185-187. PubMed.
Welshman, M. D. (1986). Doped Dobermann. The Veterinary Record, 119(20), 512. PubMed.
Henney, S. N., & Coleman, M. J. (1984). Canine cannabis intoxication. The Veterinary Record, 114(17), 436-436. PubMed.
Frost, C. (1983). Marijuana toxaemia. Veterinary Record, 112(18), 441-441. PubMed.
Godbold Jr, J. C., Hawkins, B. J., & Woodward, M. G. (1979). Acute oral marijuana poisoning in the dog. Journal of the American Veterinary Medical Association, 175(10), 1101-1102.PubMed.
Jones D L (1978) A case of cannabis ingestion. N Z Vet J 26 (5), 135-136 PubMed.
Hovda L R, Brutlag A G, Poppenga R H, Petersen K L (2016) Marijuana. In: Blackwell's Five-Minute Veterinary Consult Clinical Companion: Small Animal Toxicology, 2nd edition. Ames, Iowa, John Wiley and Sons Inc. pp 264-270.
Websites
ASPCA Animal Poison Control Center: www.aspca.org/pet-care/animal-poison-control, telephone number (888) 426-4435
Veterinary Poisons Information Service (VPIS); www.vpisglobal.com. + 44 (0) 2073 055 055