Legalization and Pet Safety: Why Policies Need to Protect Our Animals

As marijuana policies change across the nation, the conversation around its impact often centers on human health. However, it is critical to consider the impact on animals as a new study published in the Journal of the American Veterinarian Medical Association sheds light on the concern of marijuana toxicity in dogs.

Currently, the gold standard confirmatory testing for THC toxicity in dogs is costly, not easily accessible, and takes time to receive results. Thus, veterinarians often use the human urine multidrug test (HUMT) for point-of-care testing, which is unfortunately, unreliable in dogs. To rule out serious and severe conditions, HUMT is done in conjunction with additional tests such as bloodwork and advanced imaging. To understand the history, physical, neurological, and clinical-pathological findings associated with marijuana toxicity in dogs, this study analyzed the medical records of 223 dogs diagnosed with THC toxicity between January 2017 and July 2021 from a university teaching hospital. Key findings include:

• Demographics: The median age of the exposed dogs was 1 year, and the breeds varied, with mixed breeds being the most common.
• Owner Denial: Most dog owners denied the possibility of marijuana ingestion. Common stories reported were that their dog began “acting abnormal after going outside or to a public space” and when asked about marijuana being in the home, 55.6% claimed “absolutely no marijuana is in the house”.
• Clinical Signs: Most dogs developed clinical signs of toxicity within four hours of ingestion. Common clinical signs included ataxia (88.3%), hyperesthesia (75.3%), lethargy (62.8%), urinary incontinence (45.7%), and vomiting (26%). The majority (70.4%) experienced both ataxia (abnormal movement/lack of coordination) and hyperesthesia (increased sensitivity).
• Vitals and Bloodwork: While most dogs had normal vitals like heart rate, respiratory rate, and body temperature, common abnormalities included systemic hypertension (60.7%), tachycardia (37%), and hyperthermia (22.6%). Common electrolyte abnormalities included mild hyperkalemia (51.3%) and mild hypercalcemia (79.1%), with the researchers noting that this study was the first to report such abnormalities in dogs.
• Prognosis: Fortunately, all dogs survived; however, 22% were hospitalized.

The denial of dog owners in disclosing the possibility of marijuana exposure can lead to delays in diagnosis and treatment, resulting in needless testing, increased costs, and undue stress. Educating pet owners on the risks and signs of marijuana exposure and ensuring veterinarians are equipped with the tools and resources to diagnosis marijuana toxicity, are critically needed. These findings underscore the need for policies to prioritize the health and safety of pets, especially considering that many of these cases occurred within the same year as legalization in the area where the university hospital is located, as the researchers point out.