Hypochlorous Acid (HOCl) Topical

What is hypochlorous acid topical?

Hypochlorous acid (HOCl) topical (Aquacyn™, MicrocynVS®, Vetericyn Plus®, Vetericyn Plus VF®) is used for the management of skin conditions such as wounds, abscesses, abrasions, skin irritations, ulcers, post-surgical incision sites, and burns.

It may be used to prevent or treat bacterial skin infections, including methicillin-resistant staphylococcus aureus (MRSA). HOCl also has antifungal and antiviral properties and is reported to reduce inflammation, pain, and itching.

HOCl topical products are labeled for use in all animals. They are available as over-the-counter medications or veterinary prescription medications, depending on the concentration of HOCl.

The U.S. Food and Drug Administration (FDA) does not review veterinary health products (e.g., shampoos, cleansers, topical products) for safety or effectiveness before they are sold to the public. Manufacturers of veterinary health products must ensure their products are safe and labeled accurately.   

The FDA requires that these products contain a disclaimer that says, “This product is not intended to diagnose, treat, cure or prevent any disease.” Health Canada licenses “veterinary health products” after reviewing safety, efficacy, and manufacturing information provided by the manufacturer. These products are not tested by Health Canada.

Your veterinarian is the best source of information about the safety of veterinary health products in pets. These products can also have side effects, like pharmaceuticals. Although the information in this handout may be helpful, it also may be incomplete and may not represent the full range of effects this product could have on your pet. Follow your veterinarian’s directions and cautions carefully and report any concerns to them.

How is HOCl topical given?

• HOCl topical comes in varying formats for topical use. Follow your veterinarian’s instructions for use.
• Liquid solution and spray are used topically on the skin.
• Liquid gel is used topically on the skin.
• Liquid ear cleanser is used topically within the ear canal and outer ear.
• Liquid eye wash is used in and around the eye.
• Clip hair around affected skin if required.
• Take precautions to avoid bleaching or staining carpets, furniture, clothing, or jewelry.

This medication should take effect within 1 to 2 hours and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss an application, give it as soon as you remember. However, if it is almost time for the next scheduled application, skip the missed application and resume the regular schedule. Do not give extra applications.

Are there any potential side effects?

There are no known side effects from HOCl topical in animals. Products containing HOCl are generally non-toxic and safe if ingested or licked. The treated area may become red after this medication is applied due to an increase in blood flow.

Drug sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment and notify your veterinarian if you have any concerns. Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately.  

Are there any risk factors for this medication?

DO NOT USE HOCl topical in:

• Pets with corneal ulceration (if the product is intended for use in the eyes)
• Pets with a ruptured tympanic membrane (if the product is intended for use in the ears)

Although no allergic reactions have been reported, sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment and notify your veterinarian if you have any concerns.

Are there any drug interactions I should be aware of?

There are no documented drug interactions for this medication. Be sure to tell your veterinarian about any medications (including vitamins, supplements, and herbal therapies) that your pet is taking before starting any treatment.

Is any monitoring needed with this medication?

• At home, monitor for any side effects such as those noted above. If any side effects occur, discontinue the medication and contact your veterinarian. 
• Follow your veterinarian’s recommendations on when your pet needs to be rechecked and what tests are required before and during treatment with this drug.
• Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.

How do I store HOCl topical?

• Store at controlled room temperature.
• If frozen, thaw and shake contents before use.
• Keep out of reach of children and pets.
• Ask your veterinarian for specific disposal instructions. Do not flush medicines down the sink or toilet unless instructed to do so.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet's weight and symptoms. Report any adverse effects to the FDA or Health Canada.