Minoxidil and Pets: What You Need to Know

Minoxidil is a medication commonly used in people to treat types of hair loss and sometimes high blood pressure. It can come in both topical and pill form and can be safe and effective for people when used as directed. However, minoxidil poses a serious and potentially fatal risk to pets, especially cats.

Why is minoxidil dangerous to pets?

Many recognize minoxidil by brand names like Rogaine®, which is widely available over-the-counter as a topical foam or solution. Other over-the-counter products often marketed towards hair/beard growth, can also contain minoxidil-like ingredients that carry risks as well, including Aminexil®, Nanoxidil®, and Neoxyl®, amongst others.

Minoxidil works by dilating blood vessels and altering blood flow, both throughout the body and locally depending on formulation. In people, this effect can improve blood circulation to hair follicles (promoting hair growth) and lower blood pressure.

When ingested by pets, minoxidil is rapidly absorbed and can cause life-threatening complications with low blood pressure, abnormal heart rhythm, fluid build-up in the lungs and possibly cardiac or respiratory arrest. Cats are more sensitive to the effects of minoxidil than dogs and even very small exposures can cause life-threatening complications. Following ingestion, clinical signs can develop rapidly or be delayed up to 12 hours. If cardiac or respiratory signs develop, they could require veterinary treatment for up to three to four days.

What precautions can I take if I have pets in the household and I am prescribed/recommended minoxidil?

Always consult a medical professional with questions regarding proper use of over-the-counter or prescription medications and any concerns you may have regarding medications, their possible side effects or alternative treatment options.

If using minoxidil in a household with pets, extra precautions are essential:

• Store all minoxidil products securely and locked away from any pet access.
• Take oral medication or apply topical products in a closed room, away from pets.
• Clean spills immediately and thoroughly, even if they seem minor.
• Wash your hands well, immediately after application of topical products.
• Ensure topical products dry completely prior to interacting with pets.
• Prevent pets from licking or touching treated skin or sleeping on areas/items that may have residue (pillows, bedding, clothing, furniture etc.). Toxicity has been seen in cats that simply lay on pillows with minoxidil residue and then groom themselves.
• Safely dispose of tissues, towels and applicators/bottles in secured trash receptacles, away from pet access.
• If there are concerns about possible high exposure risk in a pet household, consider speaking to a medical professional about possible alternative treatment options or medications.

What if an exposure possibly occurred?

If you believe your pet has been exposed to minoxidil or if you notice any symptoms such as difficulty breathing, lethargy or weakness, seek veterinary care immediately or call ASPCA Poison Control at 888-426-4435.