With thousands of equine supplements on the market—ranging from joint support and digestive aids to calming formulas and coat enhancers—horse owners often look to veterinarians for guidance on what their animals might need. Veterinarians can help them determine when supplements are necessary for their horses, which ones are appropriate, and how to avoid ineffective or potentially harmful choices.

Start With the Forage

Carey Williams, PhD, equine extension specialist and professor at Rutgers University, in New Brunswick, New Jersey, says supplement discussions should always begin with the horse’s core diet in mind.

Forage should be the foundation, Williams says, followed by a concentrate or other commercial feed appropriate for the horse’s age, workload, and physiological status. For example, a broodmare or growing horse needs a different feed than a performance or pleasure horse. “Then you can decide—is there (a specific concern) that a supplement might help with?” she says.

If the diet is already balanced and the horse has no underlying issues, Williams says supplements might not be necessary at all.

Making Informed Equine Supplement Decisions

Once they’ve identified a need, veterinarians can help clients evaluate product options by focusing on transparency and research. “Some companies won’t be doing their own research, but they might cite published studies on ingredients in their product,” Williams says.

Veterinarians should direct owners to supplements with labels that include detailed ingredient lists, recommended dosages, and explanations of function. Vague phrases such as “proprietary blend” can be red flags. “The more specifics a company provides, the more confident I am in their product,” she says.

She also advises veterinarians to recommend ingredients rather than specific brands if they do not have a brand with which they are comfortable. “If you’re not familiar with a company, suggest functional ingredients like omega-3s from a particular source or specific antioxidants,” says Williams. “That way, the owner can do some research on their own or consult a nutritionist.”

Evaluating Equine Supplement Quality and Avoiding Risk

Quality control ranks among the most important factors to consider when choosing a supplement for your horse. Veterinarians can help clients look for companies that publish their testing protocols or quality assurance processes on their websites. “Reputable companies will show how they test their products, what methods they use, and how they ensure consistency,” Williams says.

She adds that cost can be a helpful indicator, though not a guarantee, of quality. “You do often get what you pay for,” she explains. “If a supplement is dramatically cheaper than others with similar ingredients, it should prompt questions. Is it underdosed? Has it been sitting on a shelf for years? Is the company cutting corners?”

She finds low-cost supplements from companies with limited public information or no customer support especially concerning. “Reputable companies are happy to discuss their product with you, including safety testing and research on it,” she says. “They spend a lot of money doing this, so they want everyone to know.”

Navigating Client Conversations About Equine Supplements

When a supplement serves no clear benefit or risks interfering with veterinary treatment, communication becomes essential. Williams often works alongside veterinarians during consultations to evaluate horses’ full diets and provide evidence-based recommendations.

“In cases where the vet suspects a supplement is doing more harm than good, we’ll go over the label with the client together,” she says. “Sometimes it’s not about the brand, but about the dose being too low to be effective, the supplement interacting with a medication, or they are feeding several products with overlapping ingredients.”

To help owners feel comfortable making changes to their horses’ supplement regimens, Williams recommends gradual adjustments. “I always suggest decreasing the dose first,” she says. “If they see no change, they’re usually more open to discontinuing it. It’s a good way to determine if the supplement is having an effect or not.”

Working With Equine Nutrition Professionals

Not all veterinarians are confident advising their clients about equine nutrition, which is where collaboration with a nutritionist can be helpful. Williams encourages veterinarians to contact equine extension specialists at their states’ land-grant universities, many of whom offer free or low-cost consulting.

“If a vet isn’t confident evaluating a ration, they can call someone like me,” she says. “Every state has cooperative extension, and we also have a national network. If I get a call from another state, I can help them out myself if their field is not nutrition, or I can refer them to a trusted colleague who can.”

Understanding Equine Supplement Regulation Gaps

Unlike prescription medications, equine supplements are not subject to FDA regulation, and manufacturers do not need to demonstrate efficacy before products reach the market. Veterinarians should communicate this to clients so they understand the importance of thoroughly researching supplements before purchasing them, says Williams. “That’s why it’s so important to stick with companies that are transparent, publish their ingredient lists, and explain their quality control processes,” she adds.

Williams also recommends that clients call companies directly to ask questions. “A reputable company should be able to explain what’s in their product and why,” she says. “If they avoid your questions or don’t respond at all, that’s a problem.”

Take-Home Message

Veterinarians can help clients make responsible, informed decisions about nutritional supplements for their horses. By evaluating the base diet, recommending evidence-based ingredients, and collaborating with qualified nutritionists, they can provide practical guidance grounded in science.

“There are good supplements out there,” Williams says. “But they should be used intentionally and with a clear purpose. It’s about solving a problem—not just adding something extra because they read about it online.”