Could Milk Thistle and Silymarin Prevent Laminitis?

Could Milk Thistle and Silymarin Prevent Laminitis?

Milk thistle and its extract, silymarin, are phytogenic substances—natural products known for their anti-inflammatory and antioxidant properties.

Photo: iStock

If you know your horse is at risk for the hoof disease laminitis, you can do a lot of things to help prevent the disease from occurring. You can keep his sugars and starches down to a minimum; you can keep his weight down; you can cool his feet if you suspect an inflammatory response. But now research is pointing to another method to help stave off this disease: milk thistle and silymarin.

Milk thistle and its extract, silymarin, are phytogenic substances—natural products known for their anti-inflammatory and antioxidant properties, explained Nicole Reisinger, MSc, a scientist at the BIOMIN Research Center in Tulln, Austria. Recent studies by her team suggest that these two agents could help counteract the effects of endotoxins on lamellar tissue—the part of the hoof that's damaged when laminitis sets in.

Endotoxins are toxins which are ubiquitous in the horse’s environment, she said, and are even produced in small quantities in horses' digestive tracts. But healthy horses are able to combat the effects of some endotoxins on their own. It’s when poor management, illness, antibiotics, or other immune-disrupting events occur that endotoxins can cause health problems in horses. One effect of endotoxins can be separation of the laminae—the telltale sign of laminitis.

In her study, Reisinger and her fellow researchers experimentally induced lamellar separation in 18 fresh cadaver hooves with endotoxins. They then took a separate set of extracted tissue and treated it with milk thistle or silymarin extracts together with endotoxins.

They found that milk thistle and silymarin reduced endotoxin concentrations by 64% and 75%, respectively. Both substances improved the tissue integrity and significantly reduced the incidence of lamellar separation.

While these results are exciting, it’s still far too early to start mixing milk thistle and silymarin into your feed rations, Reisinger said. Before any recommendations can be made, more research needs to be carried out—especially in living horses.

In addition, laminitis is a very complex disease with many possible causes, and it’s still not fully understood in scientific and veterinary communities, she said.

“It is important to keep in mind that laminitis is a multifactorial disease; other factors might not be counteracted with milk thistle or silymarin,” said Reisinger. “I would highlight that feed additives can only be used as a preventive or supportive strategy, not as treatment. If the horse is already suffering from laminitis, a veterinarian should be consulted immediately.”

In the meantime, until research progresses on milk thistle and silymarin, Reisinger recommends keeping a good relationship with a veterinarian when horses are at risk of laminitis.

“It is important to avoid as many risk factors as possible, especially if a horse is already susceptible to laminitis,” she said. “In addition to housing, feeding, and exercise management, application of proper mycotoxin and endotoxin risk management is crucial. A veterinarian should always be contacted to discuss preventive measurements for individual horses.”

The study, "Milk thistle extract and silymarin inhibit lipopolysaccharide induced lamellar separation of hoof explants in vitro," was published in Toxins. 

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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