🪳 Vet Guide 2025: Treating Mite-Related Pastern Dermatitis in Horses – What Works and What Doesn’t 🐴🧴

Author: Dr Duncan Houston, BVSc

Pastern dermatitis is already a frustrating condition for horse owners—but when it's caused by mites, it can be even more challenging to manage. Draft horses and breeds with feathers on their lower legs are especially vulnerable. This 2025 guide by Dr Duncan Houston explains the real causes of mite-related pastern dermatitis, debunks outdated treatments, and outlines a modern veterinary approach to effective care and prevention. 🐎📘

🔍 What Is Mite-Related Pastern Dermatitis?

Pastern dermatitis is a painful and inflammatory condition of the skin at the back of the pastern and sometimes up to the cannon bone. When caused by microscopic skin mites—especially Chorioptes mites—it leads to persistent irritation, scabbing, and secondary bacterial infections. 🦠🩹

These mites are not always visible to the naked eye, and diagnosis often requires skin scrapings or biopsy by a veterinarian. Draft breeds like Clydesdales and Shires are especially prone due to their heavy feathering, which creates a moist, mite-friendly environment. 🐴🧬

🚫 The Myth of Dewormers Like Quest and Ivermectin

In the past, some believed that oral dewormers like Quest (moxidectin) or ivermectin could effectively treat mite infestations causing pastern dermatitis. These medications are systemic antiparasitics, and while they’re effective for internal parasites, research shows they don’t work on skin mites affecting horses’ legs. ❌💊

🧪 Study Breakdown:

• 📆 Horses were given Quest orally on day 0 and again on day 21.
• 🧹 Stalls were disinfected on day 0 and 14 to minimize reinfection.
• 🧪 Mite counts were tracked in treated and placebo groups.

Result: Horses treated with Quest had just as many mites as the control group. Systemic dewormers alone were ineffective. 🧪🚫

✅ Effective Treatments in 2025: What Really Works

The most reliable treatment involves a combination of topical, systemic, and environmental strategies. Here's a step-by-step veterinary-approved plan:

1️⃣ Clip the Feathers

As unpopular as it may be, clipping the long hair or feathers around the pastern is essential. It improves visibility, allows treatment to reach the skin, and prevents mites from hiding in dense fur. ✂️🐾

2️⃣ Topical Mite Treatments

Apply lime sulfur dip or fipronil-based sprays (such as Frontline) directly to the affected area. These are highly effective at killing mites on contact. 🧴🔥

• 🟡 Lime sulfur: Apply every 5–7 days for 3–4 weeks.
• 🔵 Fipronil spray: Use every 2–3 weeks based on severity and vet recommendation.

3️⃣ Systemic Antibiotics

Since mite damage often leads to secondary bacterial infections, systemic antibiotics are commonly prescribed. This helps reduce inflammation and prevent deeper infections. 💊🛡️

4️⃣ Topical Antibiotic & Steroid Cream

After mite-killing treatments, apply an antibiotic + corticosteroid ointment to soothe the area, reduce inflammation, and support skin healing. 🧴🌿

5️⃣ Disinfection & Biosecurity

Clean and disinfect stalls, grooming tools, and blankets regularly. Mites can survive in bedding and be reintroduced to clean skin. 🧼🏡

📋 Monitoring & Follow-Up

Even after visible signs improve, mites may linger below the skin’s surface. Continue topical treatment for 2 weeks beyond the resolution of visible symptoms. 📅🔁

🚫 What to Avoid

• ❌ Ignoring scabs or hoping they “fall off” naturally—mites persist.
• ❌ Using oral dewormers alone—ineffective against skin mites.
• ❌ Skipping clipping—hair traps mites and limits medication penetration.

🐴 Breeds at Higher Risk

Draft breeds and horses with heavy leg feathering are at higher risk. This includes:

• 🛡️ Clydesdales
• 🛡️ Shires
• 🛡️ Friesians
• 🛡️ Gypsy Vanners

Regular feather maintenance and early mite detection are especially important in these breeds. ✂️🔍

🧠 Expert Tip from Dr Duncan Houston

"If your horse has pastern dermatitis that isn’t improving with standard care, think mites. A simple skin scraping could lead to the right treatment and long-term relief." 🐴🧪

🔚 Final Thoughts: Managing Mite-Induced Pastern Dermatitis in 2025

While oral dewormers like Quest may seem convenient, they’re not the solution for mite-driven skin problems in horses. Effective treatment combines topical mite control, infection management, and environmental cleanup. Early action and consistent care can prevent scarring, chronic pain, and long-term lameness. 🐎🛠️

Need help creating a customized treatment plan? Visit AskAVet.com or download the Ask A Vet app today for 24/7 vet support. Your horse deserves expert care—anytime, anywhere! 📱👨‍⚕️