The use of minoxidil on the damage to the pet

Minoxidil: A Vasodilator with Potential Risks for Pets

Minoxidil, originally developed as a vasodilator to treat hypertension, has gained attention for its unintended side effect of promoting hair growth. This led to its topical use as a hair growth agent. While it can be effective for humans, it is important to understand the potential risks associated with minoxidil when it comes to our furry friends.

The Mechanism of Action: How Minoxidil Works

Minoxidil operates by opening potassium ATP channels, which results in membrane hyperpolarization. This process leads to vasodilation and an increase in blood supply to the hair follicles. Previous research has suggested that minoxidil may mediate the vasodilator response by impeding the uptake of calcium by cell membranes, thereby affecting vascular smooth muscle.

Toxicity in Cats: Understanding the Problem

Minoxidil is metabolized in the liver, where it undergoes processes such as glucuronidation, hydroxylation, and sulfation before being excreted in urine. The issue arises in cats as they lack specific enzymes involved in the glucuronidation process, including UGT1A6 and UGT1A9. Consequently, the metabolism of certain drugs, like acetaminophen, can be notably slow in cats.

Real Cases and Evidence

A comprehensive study examining 211 cases of localized minoxidil poisoning in dogs and cats revealed alarming results. Among the 78 dogs observed, 25 (32.1%) displayed signs of poisoning. Similarly, out of the 133 cats studied, a staggering 62 (46.6%) showed signs of minoxidil poisoning. Symptoms typically manifested within 1-67 hours, with some animals experiencing vomiting or drooling within a few hours. In cats, hypotension was observed as early as 3 hours (3.5 hours in dogs), while lethargy became noticeable between 3 to 36 hours. Determining exact dosage in most cases was challenging, as the amounts ingested were often very small. Shockingly, even minor exposure, such as licking minoxidil, resulted in mild to fatal consequences in 38 reported cases.

Proceed with Caution: Protecting Your Pets

It is crucial to be cautious and avoid exposing your pets to minoxidil. Even with minimal exposure, both cats and dogs are at risk of minoxidil poisoning. Take necessary precautions and ensure that your pets do not come into contact with the substance when you are using it.

References:

• Journal of Veterinary Emergency and Critical Care, 2004; 14(4): 287-292

• Journal of Dermatological Treatment, 2022; 33:4, 1896-1906

• Journal of the American Veterinary Medical Association, 2018; 252:222-226

• Journal of the American Animal Hospital Association, 2021; 57