Marijuana toxicity in pets

By Dr. Jodi Viste, DVM - Animal Care Centre of Strathmore

Little is currently known about the safe and therapeutic uses of marijuana in companion animals and there are no legal or approved products containing tetrahydrocannabinol (THC) for pets.
What we do know is that marijuana can be toxic to your pet. Even more concerning is that the cocoa and xylitol contained in many “marijuana edibles” can also be hazardous to the health of your pet.
The summary below highlights the symptoms of marijuana toxicity in your pet and safeguards we can take to reduce the risk to your pet. Why are we concerned for your pet? We have learned from research performed in Colorado state showing a four-fold increase in veterinary emergency visits due to marijuana toxicities in pets following marijuana legalization in that state.
A pet toxicity case often involves a pet that has either inadvertently eaten marijuana in the form of a joint, discarded joint, ashes or edibles, or the dog has secondarily inhaled marijuana. In pets, clinical signs typically begin 30 to 90 minutes after ingestion or inhalation, and because THC is stored in the body’s fat deposits, the effects of marijuana ingestion can last for several days.
Symptoms of ingestion of marijuana: incoordination, listlessness/lethargy, dilated pupils, slow heart rate, urinary incontinence, startled reaction or light/sound sensitivity, drooling, tremors and vomiting.
Symptoms of ingestion of xylitol: hypoglycemia (low blood sugar) and hepatic necrosis (destruction of the liver).
Symptoms of ingestion of cocoa powder or dark chocolate: vomiting, diarrhea, hyperactivity, tremors, seizures, racing heart rhythm progressing to abnormal rhythms and death in severe cases.
If you think your pet has been exposed to marijuana in any form, it is very important for all the relevant exposure information to be given to the veterinarian. If less than 30 minutes has passed since the marijuana ingestion, vomiting can be induced. After 30 minutes, your pet will be too sedated to safely induce vomiting. Activated charcoal can be given orally to reduce the absorption of the toxins. Hospitalization on intravenous fluids and supportive therapy may be indicated in moderate to severe cases.
With increased accessibility to marijuana through legalization, safeguards need to be taken to limit your pet’s exposure: safe containment of products in sealed containers, proper disposal of residue, observation when walking your pet in public places for products on the ground and avoid having a pet in a room where marijuana is being inhaled.
Marijuana can interact with other medications so if you plan to use any marijuana products in your pet, be sure your veterinarian is aware that you are doing so.
Scientific research is now underway for safe and therapeutic uses of marijuana in companion animals. Targeted uses include pain, inflammation, anxiety and epilepsy. In the meantime, until we know more, please consider the risk to your pet when handling marijuana and ask your veterinarian if you have further questions regarding your pets.