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Vet Insight: Understanding Slobbers in Horses 2025 🐴💦
By Dr Duncan Houston, BVSc
Imagine walking into the barn to find your horse drooling profusely. Naturally, you'd be alarmed—but in many cases, this excessive salivation, known as slobbers, is not as dire as it looks. It’s often caused by a naturally occurring fungal toxin in hay or pasture—especially clover. 🌱💧
In this 2025 article, Dr Duncan Houston explains what slobbers is, what causes it, when to worry, and how to protect your horse from ingesting toxic forage. 🧠🐎
1. What Is Slobbers in Horses? 💦
Slobbers syndrome is a condition in which a horse produces excessive saliva—often enough to soak the ground, bedding, or its own legs and chest. Unlike typical drooling from dental issues, slobbers usually appears suddenly in an otherwise healthy horse. 👀
Key Signs:
- 💧 Continuous drooling
- 🛏️ Wet bedding and front legs
- 🐴 Normal attitude and appetite (in mild cases)
Slobbers is alarming—but often harmless once the source is removed. 🧼
2. What Causes Slobbers? 🧫
The condition is caused by ingestion of the fungal toxin slaframine, which is produced by the fungus Rhizoctonia leguminicola. This fungus infects legumes such as:
- 🍀 Red clover (most common)
- 🌱 White clover
- 🌿 Alsike clover
- 🌾 Alfalfa
- 🌱 Cow peas, soybean, blue lupine
Slaframine acts as a parasympathomimetic agent, meaning it stimulates the salivary glands and other organs. The result: slobbering, tearing, urination, and possibly GI upset. ⚠️
3. What Does the Fungus Look Like? 🔍
Infected plants may show:
- 🟤 Bronze to black lesions on the underside of leaves
- ⚫ Patches that spread and kill the entire plant
- ☠️ Moist, discolored clover that smells “off” or moldy
The risk increases after rain, in humid conditions, or with overmature forage. 🌧️
4. Clinical Signs of Slaframine Toxicity 🧪
While most horses just slobber, higher doses of slaframine may lead to:
- 💧 Excessive tearing (epiphora)
- 💩 Mild diarrhea
- 🥱 Lethargy or appetite changes
- 🐄 Frequent urination
- 🐖 Bloating and colic-like symptoms (rare)
- ⚠️ Abortions in pregnant mares (very rare)
These signs usually resolve within 24–48 hours after removing the toxic feed. 🧹
5. Differential Diagnosis: It’s Not Always Slobbers 🤔
Excess drooling can also indicate:
- 🍎 Choke (blocked esophagus—emergency!)
- 🦷 Dental issues
- 💊 Exposure to toxic chemicals or insecticides
- 🧪 Oral ulcers or foreign bodies
- 🦠 Neurological disease (e.g., botulism)
If your horse seems distressed or has difficulty swallowing, call your vet immediately. 🩺
6. How to Manage and Prevent Slobbers 🛡️
✅ Management Tips:
- 🚫 Remove affected hay or pasture immediately
- 🌾 Switch to clean grass hay or tested forage
- ⏳ Monitor for 24–48 hours
🔍 Prevention Tips:
- 🧪 Test hay and avoid red clover during humid months
- 🌤️ Don’t feed wet, moldy, or musty-smelling hay
- 📦 Store hay in dry, well-ventilated areas
- 🔁 Rotate pastures and remove clover-dominated areas if possible
Producers and barn managers should consider hay testing during seasonal shifts, especially after a wet fall. 🌧️🌾
7. Summary Table: Slobbers Quick Facts 📋✅
| Feature | Slobbers |
|---|---|
| Cause | Slaframine toxin from red clover fungus |
| Primary Sign | Profuse salivation |
| Other Signs | Tearing, diarrhea, urination |
| Serious? | Usually no—resolves with feed removal |
| Time to Recover | 24–48 hours |
8. Final Thoughts from Dr Duncan Houston 💬
Slobbers might look dramatic—but most cases are mild and self-limiting once the source is removed. Still, it’s important to rule out more serious conditions like choke, botulism, or poisoning. Don’t ignore the signs—observe, act, and call your vet if symptoms worsen. 🧠🐴💦
Need help identifying safe hay or pasture sources? Visit AskAVet.com or download the Ask A Vet app 📲 for 24/7 equine health advice and forage management tips.
— Dr Duncan Houston, BVSc
