Clinical examination findings and electrolyte abnormalities of dogs with marijuana/tetrahydrocannabinol toxicity: 223 cases (January 2017–July 2021)

Abstract

Abstract OBJECTIVE The goal of this study was to describe the historical, physical, neurologic, and clinicopathologic findings in dogs with a definitive diagnosis of marijuana/tetrahydrocannabinol toxicity. ANIMALS A total of 223 dogs with known ingestion of marijuana or a positive tetrahydrocannabinol result on human urine multidrug test. METHODS Retrospective study from January 2017 to July 2021. RESULTS Median age was 1 year (1 month to 12 years). A common history was becoming acutely neurologic after going outside or to a public place (62/223 [27.8%]). Most owners denied possibility of exposure (152/223 [68%]). Median vitals were normal, but hyperthermia (38/212 [22.6%]), tachycardia (82/222 [37%]), and systemic hypertension (37/61 [60.7%]) were common abnormalities. The most common clinical signs included ataxia (197/223 [88.3%]), hyperesthesia (168/223 [75.3%]), urinary incontinence (102/223 [45.7%]), lethargy (140/223 [62.5%]), and vomiting (58/223 [26%]). The most common combinations of neurologic signs included ataxia and hyperesthesia (157/223 [70.4%]) and ataxia, hyperesthesia, and urinary incontinence (81/223 [36.3%]). Mild hyperkalemia (39/76 [51.3%]) and mild hypercalcemia (53/67 [79.1%]) were common. Twenty-two dogs were hospitalized. Survival was 100%. CLINICAL RELEVANCE A common presentation for marijuana toxicosis included young dogs with acute ataxia and hyperesthesia, with and without urinary incontinence, after going outside or to a public place. Vitals were often normal, but hyperthermia, tachycardia, and hypertension were common. Bloodwork was mostly normal, but mild hyperkalemia and mild ionized hypercalcemia were common. Marijuana should be high on the differential list with these history, physical examination, neurologic, and electrolyte abnormalities, regardless of owner denial or negative human urine multidrug test.