Is Minoxidil Toxic to Cats and Dogs?

If you’re here, you probably already know minoxidil — aka Rogaine® — is good for your hairline. But is minoxidil toxic to cats and dogs? And is it something you have to avoid if you have a pet with a passion for getting into your bathroom cabinet or licking your scalp? 

Unfortunately, minoxidil is toxic to cats and dogs — even in small amounts — and it can lead to death in some cases.  

Below, we’ll explain the symptoms of minoxidil poisoning to look out for and how to keep your pet safe.  

Minoxidil can be toxic to cats. Even small amounts can be harmful and minoxidil exposure can lead to serious illness or death. 

There isn’t much research into it, but we do have one paper on the topic. It’s a 2021 review that looked at the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center database. The review found 211 cases of minoxidil exposure in cats and dogs.

Out of those 211 cases, 87 animals — which included 62 cats — developed clinical signs of toxicosis, or minoxidil poisoning. 

Cats developed symptoms of minoxidil poisoning even if they’d only been exposed to small amounts.

Among the cats that developed symptoms, almost 60 percent developed moderate or major illnesses and eight of the 62 cats died. 

The review found that the most common way cats were exposed to minoxidil was by accidentally coming into contact with it. This could happen if your cat licks your skin or pillowcase or gets splashed with some minoxidil when you’re applying the product to your scalp. 

Minoxidil can be toxic to dogs. 

The 2021 review we mentioned earlier found 25 cases of dogs developing symptoms after coming into contact with minoxidil. Of those dogs, 56 percent of them developed moderate or major illness. 

Unlike cats, dogs most often came into contact with minoxidil through exploratory behavior — which could include going through your trash and finding the empty bottle, for example. 

There’s no official list of symptoms of minoxidil poisoning in cats and dogs. Symptoms may differ between cats and dogs and your pet may react differently.

Here’s what we do know. 

A 2022 case report highlights one cat that was exposed to minoxidil and experienced: 

• Lethargy 

• Dyspnea (shortness of breath)  

• Loss of appetite  

These symptoms lasted for two days before the owner brought their pet in for examination.

A physical exam found the cat had: 

• Hypothermia (low body temperature) 

• Tachypnoea (rapid breathing)

• Hypotension (low blood pressure) 

• Bilateral pulmonary crackles (sounds coming from their lungs) 

The good news here is, after treatment, the cat made a full recovery and was discharged after six days.

In dogs, we have a 2018 case report of a dog that swallowed minoxidil 5% foam. 

The dog’s symptoms included: 

• Vomiting 

• Lethargy 

• Tachycardia (rapid heart rate)

• Hypotension 

More good news here. After treatment, the dog made a full recovery in four days.

You don’t necessarily have to avoid minoxidil if you have a cat or dog — but you do need to make sure they’re not exposed to it. 

Here’s how to keep your pet safe: 

• Wash your hands thoroughly after using minoxidil 

• Keep your pet in a different room when applying minoxidil and clean up any spillages after use 

• Try not to let your pet lick your scalp 

• Wash your pillowcase regularly and keep your pet off of your pillow — consider keeping your bedroom door closed

• Keep minoxidil in a cupboard your pet can’t get into

• When throwing out minoxidil packaging, put it in a trash can your pet can’t get into

If your pet comes into contact with minoxidil or you notice any strange symptoms, get in touch with a vet straight away. 

If you’re worried about your dog or cat coming into contact with topical minoxidil, you can consider other hair loss treatments. 

Here are some of your options: 

• Oral finasteride. Finasteride (or the brand name version Propecia®) is approved by the U.S. Food and Drug Administration (FDA) for male pattern hair loss. It can slow down hair loss and promote new hair growth. It comes in a tablet form, meaning you can’t accidentally spill it on your pet and they can’t lick it off your scalp or pillowcase. As with any medication, be sure to keep your finasteride bottle in a cupboard your pet can’t access.  

• Oral minoxidil. Oral minoxidil isn’t FDA-approved for hair loss, but it’s often prescribed off-label for hair loss. Off-label means a drug is prescribed for something it isn’t approved for. Again, taking a tablet — instead of using minoxidil solution, foam, or spray — means you can keep it away from your pet more easily. 

• Supplements and hair oils. Hair care supplements and hair oils can’t necessarily stop hair loss, but they can keep your hair as healthy as possible. Our biotin gummies, for example, contain B vitamins to help your hair grow thicker and stronger. It’s best practice to keep your pet away from any product you use.

Minoxidil is good for hair loss, but bad for cats and dogs. 

Here’s what pet owners need to know: 

• Minoxidil can be toxic for cats and dogs. Minoxidil toxicity can happen even with small amounts of exposure, like drops or licks. It can cause serious illness and death. Look out for lethargy, vomiting, loss of appetite, or difficulty breathing.

• Take extra care when using minoxidil. Keep your pet away from minoxidil on your scalp, pillowcase, and the bottle itself. Take extra care when applying minoxidil not to spill any on or near your pet and keep the bottle in a secure place.

• Other hair loss treatments are available. You can use minoxidil and take extra care to make sure your pet doesn’t come into contact with it. But if you’re concerned — or have a particularly troublesome pet — you can also look into other hair loss treatments like oral finasteride or oral minoxidil. 

So, if you’re already using it, start being extra careful with minoxidil use around your furry friend. 

If you’ve noticed a receding hairline, balding, or hair thinning and you’re looking into hair loss treatments, you’ve got plenty of options. And being a dog or cat owner doesn’t necessarily mean minoxidil can’t be one of these options.

With our online assessment, you can connect with a hair expert and discover the best hair loss treatments for you.