Topical minoxidil toxicosis in cats and dogs

Summary: Abstract Body: Topical minoxidil, an affordable, over-the-counter treatment for androgenetic alopecia, is widely used but its impact on pets is often overlooked. This study examined topical minoxidil exposure in cats and dogs alongside public interest. Annual poison control report volumes and topical minoxidil exposure cases from the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center (APCC) were collected 2013-2023. Cases involving oral minoxidil or co-exposure to other drugs were excluded. The proportion of yearly reports involving topical minoxidil was calculated relative to the total annual poison control cases. “Topical minoxidil” interest from Google Trends was collected 01/01/2013–12/31/2023. Correlation between normalized proportion of toxicosis reports and normalized topical minoxidil interest was evaluated using Pearson correlation. A total of 488 topical minoxidil toxicosis cases (63.5% in cats) were reported to APCC over the study period, comprising 0.02% of all reports. Most cases occurred in adult animals (71.3%), with oral exposure being the predominant route (92.2%). Exploratory behavior accounted for 68.6% of exposures. Clinical toxicosis was documented in 207 cases (42.4%), with 7 (3.4%) resulting in adverse outcomes, including 3 deaths. The average annual increases in the normalized proportion of topical minoxidil reports and in interest were 5.71 and 7.59, respectively. A strong correlation (R=0.760) was observed between normalized interest in topical minoxidil and proportion of poison control reports linked to it. We found increasing interest in topical minoxidil, strongly correlating with the rise in poison control cases attributed to topical minoxidil. When discussing the potential adverse effects of topical minoxidil with patients, dermatologists should ask about household pets and discuss topical minoxidil's risks to pets, including fatalities. It is important to counsel patients on prevention and prompt veterinary care if exposure occurs. Michael Ong¹, Brittany Parsons², Shari Lipner³ 1. MD Program, Weill Cornell Medicine, New York, NY, United States. 2. American Society for the Prevention of Cruelty to Animals, Champaign, IL, United States. 3. Department of Dermatology, Weill Cornell Medicine, New York, NY, United States. Clinical Research: Epidemiology and Observational Research