Dimethyl Sulfoxide (DMSO) Topical

What is dimethyl sulfoxide (DMSO) topical?

Dimethyl sulfoxide (DMSO) topical (brand name Domoso®) is a free-radical scavenger agent used to treat certain skin conditions in dogs and for certain types of inflammation in horses. In dogs, DMSO has been used to treat acral lick dermatitis, calcinosis cutis, and skin damage due to chemotherapy. In horses, DMSO has been used to treat local inflammation, surgical colic, and laminitis.

This medication is approved for use in horses and dogs to treat acute swelling due to trauma. It is used off label (extra label) in other animals and for other uses. Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions very carefully, as they may be significantly different from those on the label.

How do I give my pet DMSO topical?

• DMSO topical comes in ointment, gel, and liquid forms. It may be part of a combination product.
• All forms are applied topically, directly to the skin.
• Wear gloves when giving your pet this medication.
• Apply this medication using clean or sterile cotton.
• Do not allow your pet to lick or chew the affected area for at least 20 minutes after application.
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.

This medication should start to take effect within 1–2 hours.

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects from DMSO topical?

DMSO topical may cause the following side effects:

• Mild irritation, pain, or redness at site of application
• Tiredness
• Garlic or oyster-like odor

Serious adverse reactions may occur. If any of the following signs develop, stop giving DMSO topical and contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
• Cataracts
• Changes in bloodwork (calcium, kidney values, liver values)

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. Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This short-acting medication should stop working within 24 hours.

Are there any risk factors for this medication?

DO NOT USE DMSO topical in

• Animals that are allergic to any component

USE WITH CAUTION in:

• Animals with mast cell tumors
• Animals with severe liver and/or kidney disease
• Animals that are dehydrated
• Animals with low blood pressure

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with DMSO topical:

• Atropine
• Corticosteroids (e.g., dexamethasone, prednisone, prednisolone)
• Insulin
• Organophosphates, alcohol

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Your veterinarian may schedule a follow-up visit after the course of medication is complete to ensure the condition has been cleared and/or do additional testing to ensure this is the right medication for the condition present. In this case, follow your veterinarian’s directions.
• At home, monitor for any abnormal changes. If any occur, discontinue the medication and contact your veterinarian.

How do I store DMSO topical?

• Store the medication in its original, airtight container.
• Protect from air exposure and plastic.
• Keep medication out of reach of children and pets.

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.