Spain’s medicines agency warns that human minoxidil can cause severe cardiovascular toxicity in pets, especially cats. In one set of reports, 8 of 62 cats that developed symptoms died; exposure can come from contaminated hands or bedding.
Eight of the 62 cats that developed clinical signs after minoxidil exposure died, a fatality rate of 12.9%. Spain’s medicines agency says the risk can arise at home, even if a pet never directly ingests the product.
On 26 October 2026, the Agencia Española de Medicamentos y Productos Sanitarios (AEMPS) issued a safety alert warning that topical medicines containing minoxidil can cause severe cardiovascular toxicity and death in companion animals. Adults use these products to treat androgenic alopecia. Cats appear particularly susceptible.
Exposure may follow direct ingestion or contact with a person using the treatment, including when a pet licks a recently treated scalp. Contaminated hands can transfer the medicine, as can objects such as pillows and other bedding. The AEMPS says contact with treated owners was the most frequently identified route among reported feline cases.
Recognising poisoning can be difficult. Clinical signs may be nonspecific, the agency says, making it harder to link an animal’s condition to minoxidil in the home.
Reported effects include low blood pressure and reflex tachycardia. The agency also cites pulmonary oedema. Pleural effusion and congestive heart failure have been reported as well. Animals may develop weakness or lethargy; ataxia and tremors are also possible. Minoxidil is a vasodilator that stimulates hair growth when applied to the skin.
The figures cited by the AEMPS include data from the ASPCA Animal Poison Control Center in the United States. A veterinary case series examined 211 topical minoxidil exposures in dogs and cats reported between 2001 and 2019. Dogs and cats developed clinical signs after very small amounts, including a few drops or licks; 62 cats and 25 dogs showed signs, and eight of the affected cats died. The study, “Topical Minoxidil Exposures and Toxicoses in Dogs and Cats: 211 Cases,” appeared in the Journal of the American Animal Hospital Association in 2021.
A review of a European database found at least eight cases associated with minoxidil exposure. Four were reported in Spain. Belgium accounted for three cases, and one was reported in the United States. The cases involved five dogs and three cats.
The AEMPS advises contacting a veterinarian immediately after any suspected exposure, even if the animal has no symptoms. It also asks owners and veterinary professionals to report cases through NotificaVET. Greater awareness among pet owners and healthcare professionals could help identify cases earlier and improve reporting, the agency says.
