Confusion About Substitute Drugs

Q. Until approximately two years ago, I had my retired Quarter Horse on both Legend and Adequan. A change in our choice of vets convinced me that her "generic" MAP-5 and Chondroprotect were just as good and cheaper. Can you address this?

Also, is it necessary to give both the Legend and Adequan injections, or is there any research showing that just one of these will work well enough alone?


A. There is no evidence that these two products are "just as good and cheaper." Chondroprotect and MAP-5 are not generic drugs. Chondroprotect and MAP-5 are registered with the FDA as human devices, not as veterinary drugs. Chondroprotect is approved for topical wound application (like Furacin ointment) and MAP-5 is a sperm cryopreservative. Neither product has been FDA approved for safety (i.e., intramuscular, intravenous, or oral administration) nor efficacy in the management of horses with joint disease.

The manufacturing requirements (strength, potency, quality) for human devices are not sufficient to meet the standard for a veterinary or human drug. Don't hold this against your veterinarian; many have been misled or misinterpreted the facts on this issue. Regarding your second question: Both do different things. Many horses respond to one or the other, while some need both.

Learn more about pioneer, generic, and compounded medications in an archived webinar at

About the Author

Joseph J. Bertone, DVM, MS, Dipl. ACVS

Joseph J. Bertone, DVM, MS, Dipl. ACVS is a professor of equine medicine at Western University of Health Science's College of Veterinary Medicine in Pomona, Ca.

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