Overview of Marijuana Exposure and Toxicity in Dogs
The recent legalization of marijuana for human medicinal treatments has increased marijuana (pot) exposure and toxicity in dogs. In fact, according to the Pet Poison Helpline, there has been approximately a 450% increase in veterinary visits and calls to animal poison hotlines from marijuana exposure and toxicity.
Marijuana, also known as “pot”, is a psychoactive drug derived from the Cannabis plant that has been around for hundreds of years. The term Marijuana most commonly refers to the tobacco product made from Cannabis leaves. There are two commonly discussed species of the Cannabis plant – Cannabis sativa and Cannabis indica. Cannabis is used for both recreational and medical purposes.
There are approximately 483 known compounds in the Cannabis plant and over 80 cannabinoids with Tetrahydrocannabinol (THC) being the most potent and psychogenic. The amount and concentration of each cannabinoid varies with the different plants and stains of plants.
THC is present in the leaves and flowering tops of the cannabis plant. Hashish, another THC containing product, is the resin extracted from the plant. The second most commonly recognized cannabinoid is cannabidiol, commonly referred to as “CBD”. The difference between the THC and CBD is that THC causes psychotropic effects (affect mentation) while CBD is felt to have limited toxicity and is not psychotropic.
The Cannabis plant is also known as “hemp” but more commonly refers to strains with less psychogenic properties because of the minimal levels of tetrahydrocannabinol (THC). In people, THC is sometimes used to alleviate nausea associated with chemotherapy, help with muscle spasms caused by multiple sclerosis, to treat seizure disorders and much more.
Unfortunately, because of the illegal nature of these drugs and the concern over societal stigmas, diagnosis and treatment are sometimes delayed. This brings up the point – what does your vet do if you bring a dog in with an illegal drug exposure? Learn the answer here.
How Does Marijuana Affect Dogs?
Dogs are usually exposed to marijuana by ingestion of the cigarettes, dried leaves, or baked products containing marijuana. There are also reports of second hand smoke causing intoxication. Sometimes, owners may intentionally give marijuana to their pets to “see what happens.”
With the legalization, there are many varieties of marijuana as well as many forms. Cannabis can be used by ingestion of various foods including candy, gummy candy, suckers, baked good, butters, as well as by smoking or vaporizing.
When inhaled or ingested, the THC enters the body and binds with neuroreceptors in the brain including norepinephrine, serotonin dopamine, and/or acetylcholine. This binding alters normal neurotransmitter function.
Signs of Marijuana Toxicity in Dogs
The most common side effects of marijuana intoxication in dogs are depression, lethargy, listlessness, loss of motor coordination or balance (stumbling), incontinence of urine, low heart rate, low blood pressure, respiratory depression, dilated pupils and glazed over eyes, vocalization such as crying or whining, agitation, drooling, vomiting, seizures and coma. Some dogs may experience hallucinations and have increased sensory stimulation to noises or fast movements.
The stereotypical dog that presents to a veterinary clinic for possible marijuana exposure is lethargic, listless, stumbling, glazed over eyes, and may dribble urine.
One danger with marijuana is that vomiting is common, and if the dog is profoundly lethargic and begins vomiting, aspiration of the vomitus into the lungs can lead to severe breathing problems and even death. This is relatively uncommon.
The signs of exposure can begin as quickly as 5 minutes to 12 hours after exposure. The signs can last from a half hour to several days depending on the amount and type ingested.
Marijuana Toxicity in Dogs: How Toxic is Marijuana?
THC is readily stored in the body’s fat tissue including the liver, brain and kidneys. The liver metabolizes it and much of it is excreted in the feces and urine.
The good news is that marijuana exposure or ingestion is rarely deadly and long-term complications are uncommon. Toxicity of marijuana is low. It takes about 1.5 grams of marijuana per pound of body weight to be fatal. Therefore, death from marijuana ingestion is not common.
The most severe problems relating to marijuana exposure or ingestion in dogs have been from high concentrations of medical grade THC.
Diagnosis of Marijuana Toxicity in Dogs
Diagnosis of marijuana ingestion or exposure in dogs is often based on the physical exam findings and history of exposure. There are urine tests to determine the presence of THC. Human tests can be used but are not dependable in dogs.
Treatment of Marijuana Toxicity in Dogs
There is no antidote for marijuana. This means that the treatment of marijuana exposure usually involves trying to eliminate the drug in their system, treat secondary signs, and provide support until the drug is eliminated from their systems.