Minoxidil Toxicosis in Cats and Dogs: A Cross‐Sectional Analysis of Social Media Reports and Public Awareness

Topical minoxidil is widely used as a first-line treatment for androgenetic alopecia and frequently prescribed off-label when treating other conditions such as telogen effluvium, alopecia areata, and scarring alopecia. Emerging evidence has documented severe and sometimes fatal toxicoses in cats and dogs exposed to minoxidil [1]. We conducted a cross-sectional analysis of publicly available social media posts to evaluate pet toxicosis from topical or oral minoxidil exposure and assess public awareness of these risks. YouTube, Facebook, Instagram, Reddit, TikTok, and Google were searched in March 2025 using related terms, including (“Rogaine” OR “minoxidil”) AND (“story”, “toxicity”, “cat”, “dog”, and “pets”). English-language posts describing minoxidil exposure in cats or dogs were included; date restrictions were not applied. While educational content was excluded, personal anecdotes in comment threads were retained. We extracted video/post characteristics, exposure details, and pet health outcomes using standardized forms. Content quality was assessed using the modified JAMA Benchmark criteria [2] and modified DISCERN tool [3], yielding a quality of 2.4/5 and 3.4/5, respectively. We identified 33 pets (27 cats, 5 dogs, and 1 unspecified), with a mean age of 8.8 years. All cases involved exposure to topical minoxidil formulations; none reported exposure to an oral minoxidil product. While 20 posts described toxic exposures, 13 described non-toxic exposures. Of the cases, 93.9% (n = 31/33) were reported by pet owners. Among cases reporting exposure routes (n = 27), oral ingestion was most common (74.1%, n = 20/27), and typically from licking treated human hair or skin. Other routes included contact with contaminated bedding or clothing (22.2%, n = 6/27) and unattended products (3.7%, n = 1/27). The timing and frequency of minoxidil exposure were not clearly reported. Most owners (93.9%, n = 31/33) were unaware of minoxidil's toxicity prior to exposure. Following absorption, symptoms appeared over a mean time frame of 5 days (n = 6). Reported pet symptoms included decreased appetite, diarrhea, lethargy, seizures, and wheezing. Death occurred in 33.3% (n = 9/27) of cats. No dog fatalities were reported, consistent with prior literature [1, 4]. This may be due to metabolic differences, as cats, unlike dogs, lack glucuronidation pathways for minoxidil clearance [5]. All data are summarized in Table 1. Asymptomatic exposures occurred via ingestion (n = 11/12) and dermal contact (n = 1/12); however, the accuracy of these reports may vary. Among these cases, 69.2% (n = 9/13) of owners expressed disbelief at potential risks, while 30.8% (n = 4/13) still believed topical minoxidil products were harmless. Despite expressing shock or regret, many owners described it as a valuable learning experience (Table 2). Some reported discontinuing topical minoxidil (n = 1), switching to oral formulations (n = 1), or avoiding initiation to reduce accidental exposure. In most cases, pet owners learned of minoxidil toxicosis only after pet exposure, with some dismissing any potential harm. Although anecdotal, these cases underscore the need for increased education on the risks of topical minoxidil in households with pets. Importantly, pet safety concerns should not deter minoxidil use when clinically indicated. Beyond the use of minoxidil, it is imperative that clinicians inform patients about other topical medications that pose a risk to companion animals, such as 5-fluorouracil, brimonidine, benzoyl peroxide, salicylates, and psoriasis creams containing calcitriol, calcipotriol (calcipotriene), or tacalcitol [5]. Clinicians and pharmacists should proactively counsel patients on safe use, including avoiding pet contact with treated skin and hair, laundering exposed items, and storing products securely [1]. Adding warning labels to minoxidil products and selecting oral minoxidil in appropriate patients may further minimize accidental household pet exposure. Limitations of this study include potential missed reports, exclusion of non-English content, poor quality of reports, and underreporting due to social desirability bias. Further research is warranted to understand the true burden of minoxidil pet toxicosis and guide targeted prevention strategies. The authors have nothing to report. Dr. Cathryn Sibbald has received honoraria from Abbvie, Leo, Pfizer, Miravo, Novartis, UCB, Sanofi/Regeneron unrelated to this work. Dr. Ilya Mukovozov has participated in advisory boards for Catalytic Health Inc., CeraVe, Galderma, Kenvue, L'Oreal Canada, Pfizer, RBC Consultants, and Sun Pharmaceuticals; received honoraria for speaking engagement from AbbVie, Novartis, Pfizer, and Sun Pharmaceuticals. Dr. Jeffrey Donovan has received honoraria from Pfizer and Vichy, has participated on advisory boards at Pfizer for payment, participates on the Board of Directors for the Scarring Alopecia Foundation, and is the active Director of the Evidence Based Hair Fellowship (EBHF) Training Program. No other authors have conflicts of interest relevant to this manuscript to disclose. The data that support the findings of this study are available from the corresponding author upon reasonable request.