Horsetail - isnt it poisonous?

Look on a list of plants poisonous to horses and you may find horsetail, this is because some species are tall scouring rush (Equisetum hyemale L.), smooth scouring rush (Equisetum laevigatum A. Br.), and marsh horsetail (Equisetum palustre L.).

Lets take a closer look at one that cane be fed to horses and the guidelines to go by.

Horsetail Herb for Horses: A Natural Source of Silica for Structural Support

Horsetail (Equisetum arvense) is one of the oldest plants on Earth, often called a “living fossil.” Looking like an unassuming weed, this plant offers several benefits for horses that require support for their bones, joints, hooves, skin, and urinary system.

Known for its high silica content, which plays a key role in maintaining connective tissue health. It also offers mild diuretic and astringent properties that make it valuable in a variety of supportive care situations.

🌿 Why feed horsetail?

The main active constituents in horsetail include:

• Silica (silicon dioxide) – Essential for collagen synthesis, calcium utilization, and structural integrity of bones, cartilage, tendons, and skin.

• Flavonoids – Provide antioxidant and anti-inflammatory properties.

• Alkaloids – Can have a mild effect on tissue toning.

• Saponins – May support the body's ability to remove waste via the kidneys.

These compounds work together to support several systems in the horse’s body.

🦴 Bone & Joint Support

Silica is a vital trace mineral involved in the formation of collagen, the protein matrix that forms the basis of connective tissue. In horses, this means stronger tendons, ligaments, cartilage, and bones. Silica also helps the body absorb and utilize calcium, making horsetail useful in:

• Horses recovering from fractures or joint injuries

• Older horses showing signs of arthritic changes

• Young, growing horses with high skeletal demands

Because of this, horsetail is often included in herbal blends aimed at supporting orthopedic strength and mobility.

🧽 Hoof, Coat & Skin Benefits

The structural proteins in hooves and skin rely heavily on collagen cross-linking and mineral integrity. Silica helps improve the quality of keratin, which can lead to:

• Stronger, more resilient hooves

• Shinier coats

• Improved skin health, particularly in horses prone to dry or flaking skin

While not a “quick fix,” consistent use of horsetail as part of a balanced herbal routine can help reinforce tissue quality over time.

💧 Urinary Support

Horsetail has long been used in traditional herbalism as a mild diuretic and astringent, helping to flush excess fluids and support kidney and bladder function. In horses, this may be helpful for:

• Promoting healthy urine output

• Supporting horses prone to mild fluid retention or inflammatory conditions

However, it’s important not to use horsetail for extended periods unless under professional guidance, as prolonged use of diuretics can alter electrolyte balance.

⚖️ Feeding Horsetail: Best Practices

• Form: Usually fed dried and chopped or powdered. Often included in herbal blends designed for structural support.

• Dosage: Approx. 5–15 grams per day for an average-sized horse (always consult a qualified professional).

• Duration: Best used in 4–6 week cycles, with breaks to prevent potential nutrient imbalance (particularly thiamine depletion with excessive use).

• Combination: Often combined with herbs like comfrey, nettle, or rosehips for synergistic effects.

🚫 Contraindications & Cautions

• Not suitable for pregnant mares

• Should not be used long-term without supervision, due to possible anti-thiamine activity (especially in crude, unprocessed form)

• Avoid if your horse has kidney disease or is on diuretic medications

Need any further advice on feeding herbs please book a free 20 minute consultation with myself. Click HERE to book.