Is Minoxidil Harmful to Cats?'

Name: Sarah

Question: I am considering starting hair loss treatment with minoxidil but I have a cat and have heard minoxidil is harmful to cats. Please can you advise me if this is true and if there is any way to use it without risking my cat's health?

Answer: Hi, Sarah. We’ve had several queries regarding high strength minoxidil use and cats over the years.

Given it would be unethical to test human hair loss treatment on cats, there is very little reliable scientific research published in medical journals about this.

However, an article from the Journal of Vetinary Emergency and Critical Care, which was published in 2004, reports on the death of two cats following their exposure to topical minoxidil liquid.

The abstract states: "Two cats with dermal exposure to topical minoxidil solution were identified from the ASPCA Animal Poison Control Center (APCC) files. Both cats were presented with lethargy and dyspnea within 36 hours of exposure. The cats were hypothermic, and had pulmonary edema and pleural effusion present on thoracic radiography. Both cats died despite supportive care. Necropsy of both cats confirmed pleural effusion and pulmonary edema and indicated cardiac compromise."

What this does not tell us is how much minoxidil the cats came into contact with and what strength the hair loss solution was.

At Belgravia we always advise patients, with or without pets, to apply minoxidil at least one hour before they go to bed and to wash their hands their hands thoroughly after each application. This applies to all minoxidil formulations and, by doing so, allows sufficient time for the medication to be absorbed into the scalp with minimal residue.

This is important because any residue on the pillow means that, not only is some of the medication wasted as it is absorbed into the pillowcase rather than the scalp, but, when there is minoxidil residue on the pillow it may come into contact with the patient's face, increasing the chances of skin irritation or the development of facial hair.

In cases where the patient is a cat owner, we would advise the same apply at least an hour before going to bed to avoid residue on the pillow. You can also take the extra precaution of changing your pillowcase frequently, even daily, if you wish.

Symptoms of possible minoxidil toxicity in cats which you should be aware of include lethargy, weakness, a rapid respiratory rate, difficulty breathing, a lack of appetite and coughing.

It goes without saying that obviously you should not apply minoxidil to your cat or let it come into contact with your medication. But, should your cat accidentally touch minoxidil, I would advise washing the paw or fur immediately to remove any residue and take them straight to the vet as soon as possible.  

As you no doubt know, cats are very curious and can easily climb onto furniture, getting into even the smallest of spaces, so I would highly recommend storing your hair loss treatment safely, perhaps in a locked cupboard.

You can find further information on this subject, here, and, if you would like further details on women's hair loss treatment, you may find an online or in-person consultation useful, where can discuss both your shedding concerns and any further queries regarding storage and application of your meds with a dedicated hair loss specialist.