Vet Tips 2025: Slobbers in Horses—When Drool Becomes a Warning Sign 🐴💦

By Dr Duncan Houston BVSc

Walking into the barn to find your horse drooling excessively can be alarming. While it might look like an emergency, one of the most common causes of this condition is something surprisingly simple: a fungus on clover or hay. This condition is called slobbers. Here's how to tell if your horse’s drool is harmless—or something serious. 💧🐎

What Is “Slobbers”? 💦🧠

“Slobbers” is the informal name for a condition caused by ingestion of slaframine—a toxin produced by a fungus found on certain legumes like red clover. The mycotoxin stimulates the salivary glands, leading to profuse drooling. 😮‍💨

Most Common Source: Red Clover 🌱

• 🍃 Red clover is the most common plant to harbor the fungus
• 🦠 Slaframine-producing fungus grows on leaves and stems
• 🎯 Especially affects plants stressed by moisture, heat, or overgrowth

The condition is typically not life-threatening but can be messy and unsettling. 💧

What Causes Slaframine Toxicity? 🧬🦠

Slaframine is produced by a fungus that begins as black to bronze patches—often on the underside of plant leaves. Over time, the fungus can spread and kill the plant. 🌿

Other Plants That Can Harbor Slaframine:

• 🍀 White clover
• 🌾 Alfalfa
• 🌱 Alsike clover
• 🌿 Soybeans
• 🌸 Blue lupine
• 🌰 Cow peas

It’s most often seen in pasture, hay, or silage—especially in moist conditions. 🧊🌧️

Clinical Signs of Slobbers 🐴💧

Besides excessive salivation, other signs may include:

• 💩 Diarrhea
• 👀 Excessive tearing
• 💦 Frequent urination
• 📉 Loss of appetite
• 🤕 Abdominal bloating or mild colic signs
• 🚨 In severe cases: abortion or even death (rare)

Thankfully, most cases resolve within 24 hours of removing the contaminated forage. ⏱️

Other Causes of Excessive Drooling in Horses 🔎🧠

While slobbers is common, don’t overlook other more serious possibilities:

• 🧱 Choke (esophageal blockage)
• 🦠 Oral trauma or infection
• 💊 Medication side effects (e.g., phenylbutazone paste lingering in mouth)
• 🧬 Neurological disease
• ☠️ Botulism or insecticide exposure

If your horse has difficulty swallowing, appears lethargic, or shows other signs of illness, call your vet immediately. 🩺

Diagnosing Slobbers: What Vets Look For 🔍🩺

Your vet will examine your horse’s mouth, check for systemic signs of illness, and ask about recent hay or pasture changes.

Diagnosis often involves:

• 👄 Oral exam
• 🌾 Hay or pasture evaluation
• 🧪 Ruling out infectious or toxic causes

If other horses on the same feed or pasture are drooling too, slaframine exposure is likely. 🧬

How to Treat Slobbers 💊🌿

In mild cases, treatment isn’t necessary. Most horses recover quickly once the contaminated feed is removed. In more severe cases, supportive care may include:

• 🧃 Electrolytes or IV fluids for dehydration
• 🧊 Cooling and shade if horses are distressed
• 💊 Anti-inflammatories if oral irritation is present

Preventing Slobbers in the Future 🧼🧠

• 🌾 Inspect hay and silage for mold or unusual coloration
• 🌦️ Avoid feeding damp hay or hay stored in wet conditions
• 🧪 Rotate pastures and avoid overgrazing in clover-rich fields
• 📦 Store hay in dry, ventilated areas

Quality forage is the best protection against slaframine and other mycotoxins. 🧊📦

Need Help Identifying a Hay Issue or Toxicity? Ask A Vet 📱🐎

If your horse is drooling excessively or you suspect contaminated hay, talk to an equine expert today at Ask A Vet.

Download the Ask A Vet app for 24/7 help with oral exams, toxicity management, hay safety, and emergency salivation cases. 🐴🩺

Final Thoughts: Don’t Dismiss the Drool 🧠💧

While “slobbers” is usually harmless, it's always worth checking out. If your horse is drooling heavily, rule out choke, toxins, or mouth injury. And always inspect hay before feeding—because prevention is easier than treatment. 🧠🐎

Worried about what your horse is eating? Visit Ask A Vet today for peace of mind and expert guidance. 🐴💙