Cannabis Flashcards
Cannabis throughout history
Cannabis, hemp, marijuana, hashish, ganga
Extensive history of use across the world: fiber for rope, clothes, and for the treatment of a long list of medical conditions.
1938 - All forms of cannabis (medical marijuana, hemp, etc.) were made illegal in all of the US.
1960s - Large resurgence of people looking into the various uses of cannabis (including animal testing).
1980s - One of the first main medical uses of cannabis that was reintroduced was as an antinausea medication for use in chemotherapy patients.
1990s – Description of the endocannabinoid system (cannabinoid receptors/endocannabinoids) in the body
2001 – Canadian Medical Marijuana Access Regulations: Patients with HIV/AIDS and other specific illnesses can be prescribed cannabis. Marijuana production and license falls under Health Canada Act.
2018 – The Cannabis Act: Recreational cannabis legalized in Canada for 18+
Endocannabinoid system means
System of receptors/signalling molecules present in all vertebrates.
Cannabinoids means
Chemicals that act on the endocannabinoid system.
Endocannabinoids means
Cannabinoid chemicals made in the body that interact with the endocannabinoid system.
Phytocannabinoid means
Cannabinoid chemicals that come from the plant. Also known as “extrinsic” cannabinoids because they come from outside your body.
Delta-9-tetrahydrocannabinol (THC) in a cannabis plant does what
An extrinsic cannabinoid found in cannabis
Main psychoactive (mind-altering) chemical in cannabis, responsible for most of the intoxicating effects that people seek - highs, lows, mellowing (and triggers the appetite stimulating portion of the brain).
NOT allowed to be recommended in the veterinary world in any form – OTHER than hemp.
Cannabidiol in a cannabis plant is
An extrinsic cannabinoid found in cannabis
Responsible for most of the possible therapeutic uses.
CBD does not produce a high or intoxication.
NOT allowed to be recommended in the veterinary world in any form.
How to tell the difference between hemp and marijuana
If the plant contains high levels of THC (>0.3%) then it is referred to as Marijuana
If it contains low levels of THC (<0.3%) then it is referred to as Hemp
Hemp is permitted in the veterinary world.
Cannibas in veterinary medicine is commonly seen when
Marijuana toxicity– Occurs from the accidental ingestion of marijuana (usually containing relatively high levels of THC).
*THC is a dose-dependent toxin in the veterinary world.
Medical marijuana– Typically CBD. Used intentionally for the medicinal benefits (usually CBD with very little to no THC).
*There are NO approved uses for CBD in the veterinary world at this time.
Marijuana toxicity clinical signs
Most common: Lethargy, GI signs (vomit/diarrhea), urinary incontinence in dogs especially, salivation, sleepiness, dilated pupils/ bloodshot eyes, low body temperature
Less common: Anorexia, pruritis
Rare: hyperesthesia, Wobbling, pacing and agitation, vocalizing, sound or light sensitivity seizures, coma, Death - The occurrence is rare but may occur at high doses
How to treat marijuana toxicity
No reversal agent-supportive care only
Induce vomiting if less than 4 hours since ingestion
Pass a gastric tube and administer charcoal. Why activated charcoal?
After those 2 things, or if ingestion occurred more than 4 hours ago:
Start IV support
Cross your fingers
Depending on how much was ingested and when, clinical signs may vary hugely (and can be fatal)
Usually takes several hours but could take days to see improvement
Toxic dose is unknown
What to do if an animal ingest marijuana less than 4 hours ago
Induce vomiting ASAP - with what?
Apomorphine in dogs
Dexmedetomidine in cats
Mechanism of action of medical CBD
Activation of the receptors in the endocannabinoid system.
Receptors are present in multiple systems throughout the body
CB1 receptor is prominent in the CNS and peripheral neurons
Basal ganglia (euphoria/emotion/hunger)
Dorsal root ganglia of the spinal chord → pain modulation
Areas of brain associated with pain modulation
Mechanism: Blocks Ca+ channels so neurons do not repolarize
CB2 receptor is prominent in immune cells and tissues
Both CB1 and CB2 are present on nociceptors.
Both CB1 and/or CB2 are present on most tissues in the body
Can a vet prescribe cannabis
NO
Pet owners may choose to use cannabis products for their pets and can discuss that with the veterinarian
Approved cannabis products for animals
The only approved cannabis products for animals are Veterinary Health Products made from Hemp
Hemp products do not contain significant levels of THC and are therefore exempt from the Cannabis Act.
They also don’t contain any other concentrated phytocannabinoids, including CBD
These products are also not allowed to make health claims.
Can be identified by a Notification Number assigned by Health Canada
Veterinarians and RVTs can sell/recommend these products to clients.
