Overview of Dimethyl Sulphoxide for Canines

 Dimethyl sulphoxide (DMSO), commonly known as  Rimso-50® or Domoso®, works as a treatment for musculoskeletal disorders, interstitial cystitis and intracranial pressure for dogs and horses.

DMSO is categorized as a free radical scavenger. DMSO is a clear, colorless liquid that is miscible with water and most organic solvents. It has anti-inflammatory properties, is a free radical scavenger, and facilitates passage of compounds across mucous membranes and the skin. In addition, DMSO has antifungal properties, has cryoprotective, radioprotective, and antiischemic effects, dissolves collagen, can cause nerve block, diuresis, is a cholinesterase inhibitor, vasodilator, and a muscle relaxant.

Following topical application of DMSO to the skin, it is rapidly absorbed and distributed widely throughout bodily tissues.

DMSO is metabolized to dimethyl sulfone and dimethly sulfide and is excreted in urine and feces. In addition, it is excreted through the lungs and skin.

Treated animals give off a characteristic garlic odor, which some people find offensive. The half-life of DMSO in humans is 12 to 15 hours. The metabolite dimethyl sulfone may persist for up to 2 weeks.

DMSO is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

Brand Names and Other Names of DMSO

DMSO has been approved by the FDA for use in humans, dogs, and horses.

Human formulations: Rimso-50® (Research Industries) [DMSO has Food and Drug Administration (FDA) approval for human use only as a preservative of organs for transplant and for treatment of interstitial cystitis].

Veterinary formulations: Domoso® (Fort Dodge)

Uses of DMSO for Dogs

DMSO has been used in a variety of situations including:

– Topical treatment of musculoskeletal disorders
– Enhancement of the percutaneous absorption of drugs
– Treatment of interstitial cystitis
– Reduction of increased intracranial pressure in severe head injury
– Topical treatment for the prevention of soft tissue injury following extravasation of cytotoxic drugs.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, DMSO can cause side effects in some animals.

DMSO should not be used in animals with known hypersensitivity or allergy to the drug.

Changes in the ocular lens, resulting in altered refractive index and lenticular opacities, may occur in dogs and other species. Frequent ophthalmologic examinations are indicted in patients receiving regular treatment with DMSO.

DMSO should not be used in pregnant animals. Neither topical nor injected DMSO should be used during pregnancy, except under the most compelling circumstances, as its safety in pregnant animals has not been demonstrated. Injected DMSO is teratogenic in laboratory animals.

Because of a potential for hepatic and renal dysfunction in patents receiving DMSO, it is advisable to check liver and renal function every 6 months.

DMSO should be handled cautiously by attending medical staff or owners applying medication as it is readily absorbed through skin. Use of gloves while handing DMSO is recommended.

Drug Interactions

DMSO should not be administered concurrently with the sulindac because: 

• It decreases the formation of an active metabolite of sulindac and thus its efficacy and
• Severe neuropathy has been reported in humans receiving these drugs simultaneously

How DMSO is Supplied

Human preparation is available as a 50% aqueous solution (in 50mL aliquots).

Veterinary preparations are available as 90% gel in 60 g or 120 g tubes and 425 g containers; 90% solution in 1 pint and 1 gallon bottles. Also, roll on versions are available.

Dosing Information of DMSO for Dogs

Medication should never be administered without first consulting your veterinarian.

The usual dose is liberal topical application up to every 6 hours; total dose not to exceed 20 g/day. Therapy is often limited to 14 days.

IMPORTANT NOTE: DMSO needs to be handled with caution. DMSO will be absorbed through the skin and carry toxic compounds across the skin. Wear rubber gloves when applying topically and use in a well ventilated area. 

Do NOT mix DMSO with any other drugs or compounds without the approval of your veterinarian. 

The use may vary widely depending on the reason for prescribing.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the treatment unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse.