Equine Drug and Supplement Options Explained

April Knudson, DVM, is an equine specialist with Merial Veterinary Services. She has a special interest in equine gastrointestinal health, infectious disease, and lameness. She holds a doctor of veterinary medicine from the University of California-Davis. Here, she answers a question about how to evaluate the products available to horse owners.

Question: There are so many different versions of drugs available to purchase for my horse. How do I know which ones really work and are safe to use?

Answer: As with any other area of equine health care, it is always best to consult your veterinarian about providing the best possible medicine, including the risks and benefits of any product before giving it to your horse. There are many companies out there making claims that their products are "just like" others you may have used, but this is often just not the case.

When you decide to buy a product--specifically a drug or a supplement--for your horse, it's important to make sure you really know what you are getting. Having a better understanding of a few definitions may help as you and your veterinarian evaluate and make decisions about your horse's health care.

Brand-Name Drug--Approved by the Food and Drug Administration (FDA), brand-name drugs must comply with the agency's strict testing, manufacturing and labeling guidelines. FDA approval of a drug means:

  • The product meets quality, purity and potency specifications;
  • Each unit is consistently manufactured under what are called "Good Manufacturing Practices";
  • The safety and efficacy of the product is based on thorough scientific review prior to approval;
  • The drug is continually monitored by the FDA after it is on the market to ensure product performance, as well as identify any concerns or questions;
  • The facilities they are made at are subject to FDA approval and inspection, even if the product isn't manufactured in the United States; and
  • These drugs are given a New Animal Drug Application number, which can be found by searching the database accessed through AnimalDrugs@FDA.

Brand-name, FDA approved drugs can either require a prescription or be available over-the-counter (OTC). In the United States, horse owners are encouraged to go to the FDA site and search a drug's name to make sure it has been manufactured to the standards they expect.

Generic Drug--Generic is frequently a misused and misunderstood term. A generic drug, for which FDA approval is still required, must contain the same active ingredients as the original formulation. The generic must also be comparable to the brand-name drug in dosage form, safety, strength, route of administration, quality, and intended use.

A generic drug is not the same as a compounded drug (more on those in a moment) nor does it simply mean an OTC version of a prescription drug. Upon FDA approval, generic drugs are given an Abbreviated New Animal Drug Application (ANADA) number. For example, despite what has been claimed in some product promotions, there are no generic versions of Merial's Ulcergard or Gastrogard (both omeprazole products).

If the drug has not been FDA-approved like brand-name and generic drugs, there are no guarantees of what may or may not be in that product or in what type of conditions it has been manufactured.

Compounded Drug--Compounding can be a confusing topic. Contributing to that confusion is the fact that some product compounding is legal, while other compounding practices may not be.

Legal compounding is the manipulation of an FDA-approved drug for the purpose of meeting the needs of a specific patient. For a drug to be legally compounded and made available to a horse owner, many rules apply, including, but not limited to:

  • A valid veterinarian-client-patient relationship exists;
  • A licensed veterinarian or pharmacist must compound the product; and
  • There must not be an FDA-approved drug available.

Examples of legal compounding include crushing a pill to create an oral suspension, adding a flavor to a commercially accessible drug, or mixing two different injectable drugs together.

Many equine drugs are illegally compounded and marketed to horse owners. It is important for horse owners to know compounded products are not approved by the FDA, and that compounders are not required to comply with the FDA's safety, efficacy, and manufacturing guidelines. For example, there have been multiple studies showing that compounded omeprazole products are not as effective and often have great variations in the amount of active ingredient versus what the label claims

Nutritional Supplements--Horse owners also have access to many nutritional and dietary supplements. While the FDA does not "object to the marketing of nutritional supplements for oral administration to companion animals," those supplements are not held to the safety and efficacy testing that FDA-approved drugs are.

Their manufacturers cannot legally make any claims of disease prevention or treatment. Horse owners should be wary of using these products as a replacement for drugs that have undergone more extensive and critical scientific review. It's never a bad idea to ask the manufacturer for peer-reviewed, published data that supports the product claims.

With all of this information, it's no wonder owners can feel confused about what products to buy for their horses. Tips that will help you navigate this maze include consulting with your veterinarian, doing your homework and asking questions if you're unsure or product claims seem too good to be true. What you learn could make a difference in your horse's health.

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