Prevalence and Characteristics of Cannabis-induced Toxicoses in Pets: Results from a Survey of Veterinarians in North America

Cannabis legalization in North America has coincided with an increase in reports of cannabis-induced toxicosis in pets, but the magnitude of this problem, as well as outcomes of these incidents remain unknown. Therefore, we examined the frequency, diagnostic criteria, clinical signs, and prognoses of cannabis toxicoses in pets in North America. We conducted an online survey between January, 2021 and April, 2021 targeting veterinarians practicing in Canada and the United States (US). Out of the 251 study participants, 191 practiced in Canada. Cannabis toxicosis was most commonly reported in dogs (n=226 veterinarians), and the number of toxicosis cases increased significantly in Canada (p<0.0001) and the US (p=0.002) after October, 2018. Frequently reported clinical signs of cannabis toxicosis included: urinary incontinence (n=195), disorientation (n=182), ataxia (n=178), lethargy (n=150), hyperesthesia (n=134), and bradycardia (n=112). Edibles were most commonly suspected to be the cause of toxicosis (n=116). The most common route of exposure was ingestion (n=135), while the most cited reason was ingestion while unattended (n=135). Cannabis toxicosis was mostly diagnosed using supportive clinical signs (n=229), the most common treatment was outpatient monitoring (n=182), and pets were most often treated as out-patients (n=103). The legalization of cannabis use in Canada and the US is likely an important factor associated with the increased cannabis toxicosis cases in pets; however, the legal status may also increase reporting. The medicinal use of cannabis by pet-owners for pets may also contribute to a portion of the reported toxicoses. Most pets that experienced cannabis toxicosis recovered completely, suggesting that most cannabis toxicoses do not result in long-term ill effects. Even though some deaths (n=16) were reported in association with cannabis toxicosis, the presence of confounders such as toxins, and underlying conditions cannot be ruled out, emphasizing the need for rigorous controlled laboratory studies to investigate this important issue.