Vet Tips 2025: Itchy Horse? Understanding Inhalant Allergies and Pruritus 🐴🌾

By Dr Duncan Houston BVSc

When your horse starts scratching, rubbing, or developing hair loss, it’s more than just annoying—it could signal inhalant allergies or other underlying causes of pruritus (itchiness). Let’s break down what to look for and how to find relief for your equine partner. 🧠🐎

Seasonal vs. Year-Round Itching 🌦️🐴

If your horse is itchy during summer but improves in winter, chances are they’re reacting to flying insect allergens. But if the itch persists into cooler seasons, the cause may be something deeper—like inhalant or food allergies, or even skin infections. 🔍

Common Allergy Triggers 🧪🌿

• 🦟 (e.g., midges or culicoides) – most common in summer
• 🌾 Pollen from trees, grass, and weeds – seasonal but can linger
• 🧼 Mold or dust in hay, bedding, or barn air
• 🥣 Food ingredients like soy, molasses, or alfalfa

Many horses experience what’s known as atopy—a skin reaction to environmental allergens. This often starts as seasonal itching but may progress to year-round discomfort. ❄️🔥

Where Do Horses Itch Most? 👁️🐴

According to Dr. Susan White, horses with atopy often scratch:

• 🧠 The face
• 🦵 Legs
• 🪮 Neck, mane, and tail

This pattern can help differentiate inhalant allergies from other causes like parasites or infections. 📋

Could It Be Food Allergies? 🥣❓

Food allergies in horses are rare—but real. If suspected, diagnosis typically involves an elimination diet over several weeks. 🧪

Steps for Elimination Diet:

1. 🥗 Start with a single, low-risk forage—such as plain grass hay
2. ❌ Remove all supplements, grains, sweet feeds, and treats
3. 🔁 Gradually reintroduce feeds one at a time, every 2–4 weeks

Common food allergens include:

• 🌿 Alfalfa and peanut hay
• 🍬 Molasses and sweet feeds
• 🌰 Soy-based concentrates

Diagnosing food allergies is slow and requires . ⚠️

Winter Itching? Consider