My horse is on Devil’s Claw Plus to relieve some swelling. I recently heard that Devil’s Claw can cause liver and kidney function to decline. Could you please tell me a little more about this herb as well as some other anti-inflammatory herbs? Do you recommend the use of such herbs? VT, Pennsylvania

Dear VT,

Hmm, I’m not sure where you heard that about Devil’s Claw. The Scientific Advisory Committee of the National Animal Supplement Council (NASC) extensively reviewed the literature on this (and every) supplement ingredient and only requires this statement on product labels containing Devil’s Claw: use with caution in animals at risk for GI ulcerations. This is because one of the active components of this herb is “bitters,” which not only stimulate the appetite but also stimulate the production of stomach acid.

I have heard that it should not be used in pregnant mares, but the NASC Scientific Review Committee did not find enough compelling evidence to support such a caution. However, it is usually better to err on the side of caution so I recommend avoiding supplements that contain Devil’s Claw while a mare is in foal.

A great paper on Devil’s Claw and other herbs was just recently published (reference below). The section on Devil’s Claw outlines the scientific evidence and word-of-mouth support for the herb’s pain-killing and anti-inflammatory properties in both humans and horses. The other herbs in the paper and their benefits include:

Bee Pollen—antioxidant, antimicrobial, antifungal, anti-inflammatory, immunoregulatory; also stimulates appetite

Echinacea—anti-inflammatory, antioxidant; immunostimulant that also increases red blood cell count and hemoglobin levels

Flaxseed—antioxidant, anti-inflammatory, chemopreventive; contains high levels of the essential fatty acid Omega-3 (alpha linolenic acid)

Garlic—antibacterial, antiviral, antifungal, antiparasitic; used as an insect repellent

Ginger—anti-inflammatory, antithrombotic, antioxidant, antibacterial; shown to reduce recovery time in horses

Ginseng—anti-inflammatory, antioxidant; immunostimulant and adaptogen

Valerian—sedative, antispasmodic; on the USEF Forbidden Substances list

Yucca—anti-inflammatory, antioxidant, antispasmodic, antiplatelet

So pretty much all of the herbs the article reviewed have anti-inflammatory properties except Valerian, which has sedating effects and is included in many calming supplements. My advice is keep using the Devil’s Claw Plus if it’s working for your horse and if not, try a supplement with a different combination of anti-inflammatory ingredients, such as MSM.

Some commonly fed herbs and other functional foods in equine nutrition: A review
Carey D. Williams and Emily A. Lamprecht
The Veterinary Journal 178 (2008) 21-31.