Minoxidil Toxicity in Pets — What Owners Need to Know

Minoxidil is a widely used, FDA-approved treatment for androgenetic hair loss in humans. However, a new scoping review highlights an important safety issue for pet owners: minoxidil exposure can be highly toxic—especially for cats.

Researchers reviewed medical literature from multiple databases and identified 94 cases of minoxidil poisoning in cats and dogs. Most exposures happened through oral ingestion (70%), but many pets—particularly cats—were exposed simply by licking minoxidil left on human skin, bedding, or towels.

Which pets were affected?

• 68 cats and 26 dogs

• Average age: 3.6 years

• Cats represented the majority of accidental exposures.

Why does minoxidil toxicity happen?

Cats are more vulnerable due to their lower body weight and their limited ability to metabolize certain toxins. Even tiny amounts can trigger severe reactions.

Common symptoms in pets

Symptoms began as early as 30 minutes after exposure and included:

• Lethargy

• Hypotension (low blood pressure)

• Tachycardia (fast heart rate)

• Breathing difficulties

• Hypothermia

• Pulmonary edema

• Poor feeding or vomiting

Vet exams often showed heart failure-like findings, fluid buildup, and abnormal blood tests.

Outcomes

• 97.8% of affected animals required hospitalization

• Cats: 14.7% died

• Dogs: 0 deaths reported

This indicates significantly higher risk for cats.

How pets are accidentally exposed

• Dogs: Mostly from exploring or eating discarded products.

• Cats: Mostly from contact with minoxidil on human skin, pillows, blankets, or clothing—even after the product seems dry.

Treatment

Veterinarians used:

• Oxygen therapy

• Warming devices

• IV fluids

• Diuretics

• Vasopressors

• Thoracocentesis

• Beta blockers

Some cats died within days despite treatment.

Key takeaway for pet owners

Although minoxidil accounts for a small percentage of pet poisonings, the widespread use of hair-loss products combined with high pet ownership means many animals may be at risk.

How to keep pets safe

• Store minoxidil securely.

• Wash hands thoroughly after use.

• Avoid letting pets lick your skin or sleep on contaminated bedding.

• Dispose of tissues, cotton pads, and bottles carefully.

• Consider oral formulations if topical use poses risks in your household.

• Seek immediate veterinary help if your pet is exposed—early treatment is critical.

Why awareness matters

This review shows an urgent need for better public education about minoxidil safety around pets, especially cats. Even small exposures can be life-threatening. Pet owners and clinicians should work together to ensure treatment for hair loss doesn’t put animals at risk.