Oral Minoxidil Toxicity in Dogs: 2 New Reports

Donovan Hair Clinic Blog · a month ago · 69 views

As many of you know, we have been interested in understanding the harms of minoxidil in cats and dogs. Dr Eric McMullen led a nice study of minoxidil toxicosis in cats and dogs we published this study in 2025. This was followed by a nice study in 2026 led by Dr Grace Xiong which was a cross sectional analysis of social media reports and public awareness.What was interesting about the McMullen et al study is that there were no cases of minoxidil toxicity in pets in our 2025 study from pets consuming oral minoxidil tablets.That has now changed.I read an interesting veterinary case report outlining 2 dogs who consumed oral minoxidil pills from their owners. The dogs became extremely sick and required advanced veterinary care. Fortunately, they survived.The two key points I’d like you to remember are: (1) Even relatively small ingestions of oral or topical minoxidil caused serious cardiovascular toxicity in two dogs. (2) Both dogs in this study developed evidence of acute heart muscle injury, but recovered completely with prompt veterinary care. The dogs developed sinus tachycardia, hypotension, and markedly elevated cardiac troponin I levels, indicating myocardial damage.As oral minoxidil use continues to increase for hair loss, accidental pet exposure may become more common. This report highlights the importance of keeping all forms of minoxidil safely out of reach of our pets.ReferenceO’Donnell AD, Daugherty S, Kuhlman L, et al. Cardiovascular complications of minoxidil toxicosis in two dogs. J Am Anim Hosp Assoc. 2026.McMullen E, Xiong G, Rayner DG, Brathwaite S, Metko D, Mehta S, et al. Minoxidil toxicosis in cats and dogs: A scoping review and call to action. J Am Acad Dermatol. 2025;93(2):522-524Xiong G, Shenderey R, McMullen E, Rayner DG, Jin YX, Mannala S, et al. Minoxidil toxicosis in cats and dogs: A cross-sectional analysis of social media reports and public awareness. Int J Dermatol. 2026;65(6):1339-1342.