Doses - DIMETHYL SULFOXIDE, DMSO
Dogs: 
a) Liberal application should be administered topically to the skin over the affected area 3-4 times daily. Total daily dosage should not exceed 20 grams (or mls of liquid) and therapy should not exceed 14 days. (Package Insert - Domoso®; Syntex Animal Health) b) An investigational protocol for the treatment of increased CSF pressure secondary to CNS trauma: 1 gram of DMSO/kg body weight IV over 45 minutes. A 10% solution may be prepared by diluting 32 ml of the 90% solution into 250 ml of sterile water for injection; approximately 290 ml of 10% DMSO solution results. Caution: the LD50 for DMSO in dogs is 2.5 grams/kg. (Plumb 1988)
Horses: 
a) Liberal application should be administered topically to the skin over the affected area 2-3 times daily. Total daily dosage should not exceed 100 grams (or mls of liquid) and therapy should not exceed 30 days. (Package Insert - Domoso®; Syntex Animal Health) b) For treatment of cerebral edema secondary to eastern equine encephalitis (EEE): 1 g/kg as a 20% solution in D5W IV over 30 minutes once daily for up to 3 days. (Wilson 1987)
c) Adjunctive treatment of equine protozoal myeloencephalitis (EPM): 1 g/kg as a 20% solution in D5W IV over 30 minutes once to twice daily. (Brewer 1987)
d) For spinal cord injury: 1 gm/kg IV as a 20% solution in saline once daily for 3 days, then every other day for 6 days (Robinson 1987)
e) For cantharidin poisoning: 0.9 gm/kg IV as a 10% solution in polyionic fluids (Schmitz and Reagor 1987)
f) 0.25 - 1.0 grams/kg diluted in normal saline or D5W at a concentration of not more than 20%. Concentrations greater than 10% should be given slowly IV. Generally felt that the higher dosages are necessary to treat increased intracranial pressure and cerebral edema with twice daily dosing. At U of Minn. usual dose is 110 ml in 1 liter of saline (10%) given daily to an average sized horse. (Plumb 1988)
Monitoring Parameters -
Client Information/FDA Approval Status - Do not use non-medical grades of DMSO as they may contain harmful impurities. Wear rubber gloves when applying topically. DMSO should be applied with clean or sterile cotton to minimize the chances for contaminating with potentially harmful substances. Apply only to clean, dry skin. Use in well ventilated area; avoid inhalation and contact with eyes. May damage some fabrics. Keep lid tightly on container when not in use. Keep out of reach of children. Do not mix with any other substance without veterinarian's approval.
Selected DMSO products are approved for use in dogs and in horses not intended for food purposes. It is a veterinary prescription (Rx) drug.
Dosage Forms/Preparations -
Veterinary Approved Products:
Dimethyl Sulfoxide Veterinary Gel 90%; Domoso® (Fort Dodge) Gel 90% (medical grade) in 60 g., and 120 g. tubes, and 425 g. jars.
Dimethyl Sulfoxide Veterinary Solution 90%; Domoso® (Fort Dodge) 90% (medical grade) in 4 oz spray bottle, 16 oz., and 1 gallon bottles
Human Approved Products:
Dimethylsulfoxide Solution 50 % aqueous solution in 50 mls and 70% solution in 250 mls;
Rimso-50® (Research Industries) (Rx);Rimso-50® (Roberts);Kemsol® (Horner); (Rx)
Note: A topical otic product, Synotic® (Fort Dodge) which contains: DMSO 60% and fluocinoloneacetonide 0.01% is also available for veterinary use. Supplied in 8 ml and 60 ml dropper bottles.
For more information, refer to the excellent article reviewing DMSO by Brayton. (Brayton, CF.
Dimethyl Sulfoxide (DMSO): A Review, Cornell Vet., 1986, 76; 61-90)