Vet Insight: Free Fecal Water Syndrome in Horses Isn’t Diarrhea 2025 💩🐴

By Dr Duncan Houston, BVSc

At first glance, Free Fecal Water Syndrome (FFWS) might look like diarrhea—but it’s not. The condition is frustrating, messy, and difficult to manage, but it's distinct from classic diarrhea in both appearance and cause. In 2025, we’re still uncovering the root of the problem, but new studies are helping us better understand how stress, social hierarchy, and environment contribute. 🧠💩

In this article, Dr Duncan Houston breaks down what FFWS is, how it differs from diarrhea, and what you can do to minimize the mess and improve your horse’s comfort. 🐎

1. What Is Free Fecal Water Syndrome? 💧

Unlike diarrhea, where all the stool is loose or watery, FFWS involves normal manure with excess watery discharge before, during, or after defecation. The water may:

• 💧 Drip from the anus or tail during passing
• 💩 Be mixed lightly with manure
• 🪰 Soak the tail and hind legs, attracting flies and causing skin irritation

The feces themselves appear healthy and formed—making FFWS a unique and often misunderstood problem. 🧐

2. What FFWS Is Not 🚫

FFWS is not diarrhea, and treating it like diarrhea (e.g., antibiotics, antidiarrheal meds) can do more harm than good. It's not typically caused by:

• ❌ Parasites (though routine deworming is still important)
• ❌ Dental disease
• ❌ Cold water intake
• ❌ Alfalfa or silage (though some horses are sensitive)

3. What Might Cause Free Fecal Water? 🤔

There’s no single cause—but contributing factors include:

🔹 Social Stress

• Horses lower in herd hierarchy (especially geldings)
• More common in winter when confined with dominant herd mates

🔹 Anxiety & Gut-Brain Connection

• Like humans, horses’ GI tracts are affected by stress
• Subordinate horses may experience altered motility from anxiety

🔹 Seasonal Environment

• More frequent in winter due to confinement and reduced turnout
• Stress from restricted movement and poor ventilation may play a role

4. Who Is Most Affected? 👥

According to recent studies:

• 👨‍🌾 Geldings are more likely to have FFWS than mares
• 🐎 Paint horses are statistically more prone
• 🔻 Horses with lower social rank show higher incidence

5. Clinical Concerns and Complications 🩺

FFWS is usually a nuisance rather than a medical emergency. However, it can lead to:

• 🩹 Skin infections on legs and under tail
• 🪰 Fly attraction and maggot risk in warmer months
• 🧼 Chronic soiling and staining

Always monitor for changes—if the manure becomes unformed or systemic symptoms appear, consult your vet immediately. ⚠️

6. Management Strategies ✅

🔸 Reduce Stress

• 🏞️ Increase turnout and reduce confinement
• 🤝 Rearrange group housing to reduce herd bullying
• 🧘 Add enrichment or rotate pasture to reduce anxiety

🔸 Improve Diet Gradually

• 🌾 Feed high-fiber, low-NSC forage
• 🪵 Try removing alfalfa or haylage if suspected to worsen symptoms
• 🧪 Use tested hay to avoid high sugar content

🔸 Add Probiotics (Cautiously)

• 🧫 Some horses improve with gut-supportive supplements
• 🛑 But not all products work—consult your vet before adding

🔸 Tail and Skin Care

• 🧼 Wash hindquarters daily with gentle, antiseptic shampoo
• 🛡️ Apply barrier creams to prevent irritation
• 🪰 Use fly sheets or repellents in warm weather

7. Summary Table: FFWS vs Diarrhea 📋

8. Final Thoughts from Dr Duncan Houston 💬

Free Fecal Water Syndrome is a frustrating but manageable condition. It’s not diarrhea and doesn’t usually signal serious illness—but it does indicate something’s off, often related to stress or environment. Don’t overreact with medications. Instead, focus on reducing anxiety, improving turnout, and keeping your horse clean and comfortable. 🧠🐴🧼

Need help identifying if your horse’s case is FFWS or something more serious? Visit AskAVet.com or download the Ask A Vet app 📲 for expert equine advice and condition-specific care plans.

— Dr Duncan Houston, BVSc