The hallmark clinical signs of canine cannabis/THC intoxication are ataxia, urinary incontinence, lethargy, hyperesthesia, hypersalivation, and mydriasis, with onset typically within 1.25 hours of ingestion (range 0.5–12 hours). Most dogs develop signs within 4 hours of ingestion.Journal of the… Ataxia is the most frequently observed sign, reported in 35 of 38 dogs in one plasma-confirmed case series.Journal of Vete… Hyperesthesia was documented in 75.2% of dogs in the largest published case series.Journal of the… Cardiovascular abnormalities, when present, are more commonly tachycardia and hypertension rather than the bradycardia and hypotension traditionally expected — though bradycardia, hypotension, and hypothermia do occur and are dose-dependent.Journal of the… In severe cases, seizures, tremors, hyperthermia, vomiting, and hypotension can occur.Journal of Vete…
Diagnosis is clinical — history combined with the characteristic sign cluster confirms the diagnosis with high specificity, and laboratory confirmation does not alter treatment decisions. Plasma cannabinoids were quantifiable in 37 of 38 dogs presenting with suspected intoxication based on history and physical examination alone.Journal of Vete… Of the clinical signs recorded, only abnormal reflexes correlated with plasma THC concentration at the time of sampling.Journal of Vete… Over-the-counter urine drug screens designed for humans measure THC-COOH and are not sensitive enough for canine urine due to low THC-COOH concentrations in dogs.Journal of Vete…
Treatment is decontamination followed by supportive care — there is no specific antidote for cannabinoids. Supportive care is the established standard.Journal of Vete… Clinicians should monitor for and address CNS depression, urinary incontinence, cardiovascular abnormalities, and thermoregulatory dysfunction. Because cannabinoids are potent inhibitors of cytochrome P450 enzymes (particularly cannabidiol/CBD), any co-administered drugs should be reviewed for interactions, and hepatic enzyme monitoring is warranted with ongoing exposure.WSAVA Global Gu… When cannabinoids are combined with calcium-channel-acting drugs such as gabapentin, doses should be reduced to avoid excessive sedation.WSAVA Global Gu…
Intravenous lipid emulsion (ILE) is a treatment option for severe or refractory cases. ILE has been used successfully in a ferret with severe cannabinoid intoxication.Journal of Vete… In dogs with severe hyperlipidemia where ILE is contraindicated, extracorporeal therapy (charcoal hemoperfusion and hemodialysis in series, 3-hour session) successfully resolved seizures and hyperesthesia refractory to multiple anticonvulsants, with significant neurologic improvement during the session and full recovery after 36 hours of post-session hospitalization.Journal of Vete…
Transmucosal cannabidiol (CBD) is an emerging treatment option for non-severe THC toxicosis. In six dogs treated with transmucosal CBD-infused dissolving sheets at 0.4–2.6 mg/kg, lethargy and ataxia noticeably improved and all additional clinical signs resolved within 45 minutes of treatment in five of six cases, with no further follow-up required for THC toxicosis in any case.Frontiers in Ve… One of the six cases also received injectable antiemetic therapy.Frontiers in Ve…
Prognosis is favorable for most cases. Biochemical findings in accidental exposures generally reflect pre-existing or non-specific conditions rather than direct cannabis effects, with no evidence of renal impairment or acute hepatic injury in mild-to-moderate cases.Frontiers in Ve… Severe cases requiring mechanical ventilation and extracorporeal therapy can achieve full recovery.Journal of Vete…
| Scenario | Intervention | Outcome | Key Caveat |
|---|---|---|---|
| Mild–moderate toxicosis | Supportive care ± transmucosal CBD 0.4–2.6 mg/kg | Signs resolved within 45 min in 5/6 dogs Frontiers in Ve… | Diagnosis is clinical; urine OTC screens unreliable in dogs Journal of Vete… |
| Severe/refractory toxicosis | ILE (if normolipemic) | Reported success in ferret Journal of Vete… | Contraindicated with severe hyperlipidemia Journal of Vete… |
| Severe toxicosis + hyperlipidemia | Charcoal hemoperfusion + hemodialysis (3-hour session) | Full recovery; ventilation discontinued during session Journal of Vete… | First-line only when ILE contraindicated |
| Any case with co-medications | Cytochrome P450 monitoring; reduce gabapentin dose | Avoids excessive sedation and hepatotoxicity WSAVA Global Gu… | CBD is a potent CYP450 inhibitor WSAVA Global Gu… |
Would you like guidance on when to induce emesis or administer activated charcoal in the acute decontamination window for THC ingestion?