What is THC/CBD poisoning?
THC or delta-9-tetranhydrocannabidiol is one of over 100 chemical compounds in Cannabis spp. (marijuana) plants. THC is psychoactive, meaning exposure leads to changes in consciousness and perception. Pets may be exposed to THC in its plant form (flowering bud, leaves, stems, roots) from a legal or illegal product. Plant-based THC products include edibles (foods), oils, tinctures, balms, capsules, vaping liquids, hashish, and concentrates. There is no current veterinary therapeutic indication for THC in animals and exposure by oral or inhalation route leads to clinical signs at low doses.
Cannabidiol or CBD is a non-psychoactive chemical compound derived from any Cannabis spp., with the Cannabis sativa (hemp) plant being the most common. CBD is available as cream, oil, mist, drops, tablets, gummies, soft chews, and food formulations. CBD products for animals have been touted to treat osteoarthritis, separation anxiety, seizures, and neoplastic (cancer) pain. Veterinary scientific evidence is limited regarding the effectiveness of CBD for these disorders, but research is actively occurring. Poisoning may occur following ingestion of a CBD overdose by pet animals.
What are the clinical signs of THC/CBD poisoning?
Within minutes of inhalation and up to an hour after ingestion of THC, pets can exhibit clinical signs. Common signs include neurologic and cardiovascular depression. Less common clinical signs include blood pressure changes, urine dribbling, and aggressive behavior/agitation. Large overdoses of Cannabis-derived THC or exposure to synthetic THC (e.g., illicit products dubbed “Spice” or “K2”) lead to dangerous clinical signs including respiratory depression, seizures, and coma.
"CBD has a wider margin of safety than THC and is less likely to cause poisoning."
CBD has a wider margin of safety than THC and is less likely to cause poisoning, in part because it is not psychoactive. Clinical signs associated with CBD overdose are most commonly vomiting and diarrhea. However, CBD products are poorly regulated and may be contaminated or adulterated with THC above the legal limit for hemp-based products. Pets ingesting large overdoses of THC-contaminated CBD can develop clinical signs of THC poisoning.
How is THC/CBD poisoning diagnosed?
THC/CBD poisoning is diagnosed by veterinarians in pets that have a history of exposure to these products followed by rapid onset of the expected clinical signs. Human on-site urine drug tests often return false negative results for pets, and so are minimally useful for diagnosing THC poisoning in veterinary settings.
How is THC/CBD poisoning treated?
If a potentially poisonous amount of CBD or THC was recently ingested by a dog, and the dog is not showing signs, induction of vomiting may be indicated, followed by administration of medical grade activated charcoal. Pets with moderate gastrointestinal signs of CBD poisoning are treated with anti-nausea and anti-diarrheal medications; hospitalization is not usually required. Hospitalization to monitor vital signs, neurological signs and blood pressure is required for animals showing more serious signs of THC poisoning.
What is the prognosis for THC/CBD poisoning?
The prognosis for recovery from CBD poisoning is excellent, with resolution of signs typically within 24 hours. The prognosis for recovery from THC poisoning is dependent on the ingested dose. For pets ingesting a small to moderate dose of THC, the prognosis is good; full recovery is expected within three days. Conversely, pets ingesting high doses of THC or synthetic THC (Spice/K2) have a worse prognosis for recovery, and death has been reported.
If you suspect your pet has been exposed to a THC or CBD containing product that was not intended for their use, immediately call your veterinarian or Pet Poison Helpline, a 24/7 pet poison control center, at 1-800-213-6680.
Pet Poison Helpline, an animal poison control center based out of Minneapolis, MN, is available 24/7 for pet owners and veterinary professionals that require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals, and exotic species. As the most cost-effective option for animal poison control care, Pet Poison Helpline’s per-incident fee includes follow-up consultations for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at www.petpoisonhelpline.com.
