THC and CBD Poisoning

What is THC and CBD poisoning?

THC (delta-9-tetrahydrocannabinol) is one of over 100 chemical compounds in Cannabis spp. (marijuana) plants. THC is psychoactive, which means that 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.

CBD (cannabidiol) 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 and 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 signs include blood pressure changes, urine dribbling, and aggressive behavior or 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, 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 are THC and CBD poisoning diagnosed?

THC and CBD poisoning are diagnosed by veterinarians in pets that have a history of exposure to these products followed by rapid onset of the expected clinical signs. Urine drug tests designed for humans often return false negative results for pets, and so are minimally useful for diagnosing THC poisoning in veterinary settings.

How are THC and CBD poisoning treated?

If a dog recently ingested a potentially poisonous amount of THC or CBD, and the dog is not showing signs, induction of vomiting may be required, followed by administration of medical grade activated charcoal. 

Pets with moderate gastrointestinal signs of CBD poisoning are treated with supportive care, and hospitalization is not usually required. Hospitalization to monitor vital signs, neurological signs, and blood pressure is required for animals that show more serious signs of THC poisoning.

What is the prognosis for THC and CBD poisoning?

The prognosis for recovery from CBD poisoning is excellent, with signs typically resolving within 24 hours. The prognosis for recovery from THC poisoning depends on the ingested dose. 

• For pets that ingest a small to moderate dose of THC, the prognosis is good, and full recovery is expected within three days. 
• For pets that ingest high doses of THC or synthetic THC (Spice or K2), the prognosis is worse, 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 center, at 1-800-213-6680.

Pet Poison Helpline, an animal poison 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.