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 (Cannabis 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 in cream, oil, mist, drops, tablet, gummy, soft chew and food formulations. CBD products for animals have been touted to treat osteoarthritis, separation anxiety, seizures, and neoplastic pain. Veterinary scientific evidence is limited regarding the effectiveness of CBD for these disorders, but research is actively occurring. As of January 2021, there is a single FDA-approved CBD drug (Epidiolex®) for humans, but no veterinary-labeled, FDA-approved CBD products for animals. State and federal laws vary regarding the marketing of CBD products for therapeutic and medicinal use in both humans and animals. Regulations for your specific state should be considered when considering purchasing or using CBD products for your pet. Poisoning may occur following ingesion 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: sleepiness, flinching when stimulated, stumbling gait or inability to walk, vomiting, and reduced heartrate. Less common clinical signs are low blood pressure, 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”) – leads to dangerous clinical signs including respiratory depression, seizure, and coma.
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 toxicity. If you suspect your pet has been exposed to a THC or CBD containing product that was not intended for their use, please call your veterinarian or Pet Poison Helpline, a 24/7 animal poison control center, at 1-800-213-6680 right away.
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 (THC) often return false negative results for pets so are minimally useful for diagnosing THC poisoning in veterinary settings. If a confirmed diagnosis is necessary, urine may be submitted to an off-site diagnostic laboratory for specific testing; this process usually takes several days.
How is THC/CBD poisoning treated?
If a potentially toxic amount of CBD or THC was recently ingested by a dog, induction of vomiting followed by administration of activated charcoal may be dependent upon the formulation of the product in pets already showing signs and/or pets ingesting oil, lotion, or liquid formulation products, inducing vomiting requires caution. 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. Treatment includes intravenous (IV) fluids, anxiolytics, and anti-nausea medication. Mechanical ventilation, anticonvulsants, and IV Intralipid emulsion (IVLE) – a sterile fat solution used to assist elimination of specific poisons- may be needed in pets with life-threatening signs.
What is the prognosis for THC/CBD poisoning?
The prognosis for recovery from CBD poisoning is excellent with resolution of signs within 24 hours. The prognosis for recovery from THC poisoning is dependent upon the ingested dose. For pets ingesting a small to moderate dose of THC the prognosis is good; full recovery is expected within 3 days. Conversely, pets ingesting high doses of THC or ingesting synthetic THC (Spice/K2) have a worsened prognosis for recovery and death has been reported.
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 fee of $65 per incident 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