Rogaine Is Toxic to Cats and Dogs—Here's How to Keep Your Hair and Your Pet

I started losing my hair when I was 25. I thought about using minoxidil — the active ingredient in Rogaine — but I worried about having to apply a topical treatment to my scalp every day. I wasn’t concerned about the side effects or anything. I just felt like if I added another step to my daily routine — especially one that was so fiddly, messy, and time consuming — it would be doomed to abandonment after a week or two.

Also, Rogaine was expensive. Propecia was expensive, too, but taking a pill once a day felt much more manageable than twice daily minoxidil applications. So, I went with Propecia, which soon became available in a much more affordable generic called finasteride, and my hair stopped falling out. I have to keep taking that pill for the rest of my life, but I’ve experienced no side effects, so, at this point, I’m fairly confident that finasteride is and was the right choice for me. And, as it turns out, it has been the right choice for my cats as well. Rogaine (namely its main effective ingredient, minoxidil) is toxic to both kitties and pups.

Your pet should never come into contact with Rogaine.

“Minoxidil is highly toxic to both dogs and cats, even in small amounts,” says Dr. Nita Vasudevan, a veterinarian at Embrace Pet Insurance. “Exposure can cause severe cardiovascular effects, including low blood pressure (hypotension), rapid heart rate (tachycardia), fluid buildup in the lungs (pulmonary edema), and even death in severe cases.”

Though minoxidil toxicity is not as frequently reported as some other household toxins, she warns that the risk is still very real. Indeed, a study published in 2021 looked at 211 cases of topical minoxidil exposure among cats and dogs from 2001 to 2019. Of those, 87 cases showed clinical signs of toxicosis with most pets developing moderate or major illness (56.0 percent dogs, 59.7 percent cats) and death occurring in about 12.9 percent of cats. And these are just the cases we know about. “Many cases likely go undiagnosed,” she says, “especially if pet owners don’t realize their animals were exposed.”

So, how do pets become exposed to minoxidil in the first place? Unintentionally, of course. It’s not like anyone is applying minoxidil to their pet’s bald spots to give them a more full and lustrous coat. And if you are doing that, please stop immediately. According to the study, dogs were most commonly exposed when they rooted through the trash. Cats’ exposure resulted from licking their parent’s hair or pillowcase after application or being splashed with minoxidil during a medication spill. 

“Pets can be also exposed by licking your skin after application,” Dr. Vasudevan says. “Even if the product has dried, residue may remain. Cats, in particular, groom themselves frequently and may ingest minoxidil if they rub against your treated skin or sit where you’ve rested. If a pet steps in spilled liquid or chews on a used applicator, they can absorb a toxic dose. While less common, spray formulations could potentially settle on fur or be inhaled.”

So, if Rogaine is your go-to, what should you do?

Does this mean you should you stop using minoxidil? That’s really between you, your doctor, and your vet. The fact is that our homes are full of things that can be toxic if consumed by our pets, including foods like chocolate and raisins, and products we use to clean our pots and pans. But just because something is toxic when eaten or misused doesn’t mean we have to banish it from our lives altogether.

“If you choose to continue using minoxidil, apply it at night, and cover the application area with clothing before interacting with your pet and wash your hands thoroughly after applying,” Dr. Vasudevan says. “Avoid letting pets lick your skin or lay on bedding/clothing that may have absorbed residue.”

Of course, limiting interactions with your pets in this way may be difficult. I could certainly never do it. Sharing the bed with my cats has always been one of the best things about having them, and I can’t imagine giving it up. And as for the hair-licking, well, my cats have never been big on it, but some cats do it all the time. If you enjoy being groomed by your cat (or getting kisses from your dog), you may not want to give it up.

So, what other choices do you have for hair-loss treatment?

You always have the option of trying something else. Fortunately, minoxidil is not the only available product on the market for combatting hair loss. Finasteride is also a highly effective treatment, as has been my experience. Although it is only approved for use by men, some providers do prescribe it to women off-label, especially post-menopause when other interventions — including minoxidil — prove ineffective.

Of course, finasteride has potential side effects: “It may lead to sexual dysfunction, decreased libido, decreased sperm counts, tender enlarged breasts, and depression including suicidal thoughts, among other side effects,” says Dr. Viktoryia Kazlouskaya of Dermatology Circle in New York City.

That said, side effects are possible with any medication. Even minoxidil has potential side effects, Dr. Kazlouskaya says. She says these include “increased hair growth in unintended areas, palpitations, tingling sensations, headaches, and allergic reactions. [It] can also cause water retention, leading to leg swelling, under-eye puffiness, and, in rare cases, dangerous fluid buildup around internal organs.” (You should always consult your doctor about any side effects before using a new product.)

And, of course, finasteride, like minoxidil, is also toxic to pets, but only in large amounts, so as long as your pets can’t open your pill containers and eat their contents, they should be fine. “In some cases, [finasteride] is even used in veterinary medicine to treat certain urinary tract conditions, ” Dr. Kazlouskaya adds. That is not to say that it is safe, but just that, like with all things, the degree of the danger is dependent on quantity and context.

As for other, completely non-toxic treatments, it’s best to consult a doctor before embarking on any sort of hair-loss intervention. “Finasteride and minoxidil remain the most effective FDA-approved medications for hair loss,” Dr. Kazlouskaya says. “[Pursuing] alternatives without a proper consultation with a professional may delay treatment and management, potentially leading to more progressive hair loss.

And while other treatments, such as natural remedies like oils or supplements, and in-office procedures, like PRP injections and laser treatments, are gaining popularity, their efficacy may be lower than that of minoxidil and finasteride.”

What should you do if your pet consumes any of these chemicals?

All of this is to say that you don’t necessarily have to choose between keeping your pet and keeping your hair. You just need to be careful and conscientious and go in with your eyes wide open. At least now you know what’s at stake and what you can do to mitigate the risks.

If you choose to go the minoxidil route, make sure you keep your containers locked up tight, keep your pets out of the room when you are applying them and clean up thoroughly after application, including washing your hands before touching your pet.

Keep them off the bed, and don’t let them lay on any clothing where there might have even a tiny amount of minoxidil residue. “And if you suspect your pet has been exposed, seek veterinary care immediately,” Dr. Vasudevan says. “Symptoms may take hours to appear, but early intervention can improve outcomes.”

References

Maguire, Cheryl. “Does Finasteride Work for Women?” The Checkup, 3 May 2022, www.singlecare.com/blog/finasteride-for-women/.

Tater, Kathy C., et al. “Topical Minoxidil Exposures and Toxicoses in Dogs and Cats: 211 Cases (2001–2019).” Journal of the American Animal Hospital Association, vol. 57, no. 5, 8 Aug. 2021, pp. 225–231, https://doi.org/10.5326/jaaha-ms-7154.