Slobbers in Horses

Slobbers in Horses: What It Means and When to Worry

By Dr Duncan Houston

Walking into the barn and seeing a horse dripping saliva can be alarming. It often looks dramatic, with wet legs, soaked bedding, and saliva literally pooling on the ground. The good news is that in many cases, this condition, commonly called slobbers, is not dangerous and resolves quickly once the source is removed.

The important part is knowing when it is harmless and when it is something more serious. Excess salivation can look similar across very different conditions, and some of those do require urgent attention.

Quick Answer

Slobbers in horses is most commonly caused by a fungal toxin called slaframine, usually found in clover-infected pasture or hay. It leads to excessive salivation but is typically harmless and resolves within 24 to 48 hours after removing the source. However, if the horse is distressed, struggling to swallow, or showing other signs of illness, it may be something more serious and should be assessed by a veterinarian.

What Is Slobbers in Horses?

Slobbers is a condition where a horse produces excessive saliva, often to a surprising degree. Horses may drip constantly, leaving wet patches on their chest, front legs, and stall floor.

Typical features include:

• sudden onset

• large volumes of saliva

• otherwise normal behavior in mild cases

• continued eating and drinking in uncomplicated cases

The key detail is that most horses with simple slobbers look bright and comfortable despite the amount of drooling.

What Causes Slobbers?

The most common cause is ingestion of slaframine, a toxin produced by a fungus that infects certain legumes.

The fungus involved is commonly associated with:

• red clover

• white clover

• alsike clover

• alfalfa and some other legumes

Slaframine stimulates the parasympathetic nervous system, which increases salivary gland activity. That is why the drooling can be so dramatic.

Decision checkpoint

If multiple horses on the same pasture or hay source start drooling at the same time, clover-related slobbers is very likely.

When Does Slobbers Usually Occur?

Slobbers tends to show up when conditions favor fungal growth.

Higher-risk conditions include:

• warm, humid weather

• recent rainfall

• overgrown or mature pasture

• poorly dried or stored hay

• clover-heavy fields

This is why slobbers is often seasonal and may appear suddenly after weather changes.

What Does Affected Forage Look Like?

Infected clover or forage may show:

• dark or black patches on leaves

• brown or bronze discoloration

• areas of plant die-off

• damp or musty-smelling hay

However, not all contaminated forage is obvious. Some of the most problematic hay looks relatively normal.

What Signs Do Horses Show?

Mild and common signs

• profuse salivation

• wet muzzle, chest, and legs

• otherwise normal attitude

• normal appetite in many cases

Moderate signs

• tearing from the eyes

• mild diarrhea

• increased urination

• slight lethargy

Less common but more concerning signs

• reduced appetite

• more obvious discomfort

• mild colic signs

• bloating

Rare but important

• reproductive issues in pregnant mares

• more significant gastrointestinal disturbance

Severity Framework: How Worried Should You Be?

Mild

• horse is bright and eating

• drooling is the main sign

• no distress or abnormal behavior

Action: Remove suspected forage and monitor.

Moderate

• drooling plus mild diarrhea or tearing

• slight dullness

• still stable overall

Action: Remove source and monitor closely over 24 to 48 hours.

High concern

• reduced appetite

• signs of discomfort

• worsening clinical signs

• dehydration risk from excessive fluid loss

Action: Veterinary advice is recommended.

Critical concern

• difficulty swallowing

• feed or water coming out of the nose

• signs of choke

• neurological signs

• severe depression or colic

Action: This is not typical slobbers. Contact a veterinarian immediately.

How Quickly Do Horses Recover?

In straightforward cases, recovery is usually rapid once the source is removed.

Typical timeline:

• improvement begins within hours

• most cases resolve within 24 to 48 hours

If signs persist beyond this, or worsen, the diagnosis should be reconsidered.

When It Is Not Slobbers

This is where caution matters. Not all drooling is harmless.

Other possible causes include:

• choke, which is an emergency

• dental problems

• oral ulcers or foreign bodies

• toxin exposure from chemicals or plants

• neurological disease

• severe gastrointestinal disease

Decision checkpoint

If the horse cannot swallow properly, looks distressed, or is not acting normal, assume it is not simple slobbers until proven otherwise.

How to Manage Slobbers

Immediate steps

• remove access to suspected hay or pasture

• provide clean, safe forage

• ensure access to fresh water

• monitor the horse closely

Supportive care

Most horses do not need treatment beyond removing the source, but monitoring is important to ensure signs are resolving.

How to Prevent Slobbers

Manage forage sources

• avoid feeding moldy or musty hay

• be cautious with clover-heavy hay

• inspect forage regularly

Manage pasture

• rotate grazing areas

• reduce heavy clover dominance where possible

• monitor fields after wet conditions

Store hay properly

• keep hay dry and well ventilated

• avoid prolonged damp storage conditions

Consider testing when needed

If issues recur, forage testing may help identify underlying problems.

Common Mistakes Owners Make

Assuming all drooling is harmless

This can delay recognition of serious conditions like choke.

Continuing to feed the same hay

If the source is not removed, the problem continues.

Ignoring herd patterns

If multiple horses are affected, it is almost always environmental.

Waiting too long to reassess

If signs do not improve quickly, the diagnosis may be wrong.

Slobbers at a Glance

FAQs

Is slobbers dangerous for horses?

Most cases are mild and resolve quickly, but it is important to rule out more serious causes of drooling.

Can slobbers affect multiple horses at once?

Yes. It often affects several horses sharing the same forage source.

Should I call a vet for slobbers?

If the horse is otherwise normal, you can monitor initially. If there are additional signs or no improvement, call your vet.

Can hay cause slobbers as well as pasture?

Yes. Clover-contaminated hay can also contain the toxin.

How do I tell slobbers from choke?

Choke often involves difficulty swallowing, distress, and feed or water coming out of the nose. That is an emergency.

Final Thoughts

Slobbers is one of those conditions that looks far worse than it usually is. The amount of saliva can be dramatic, but most cases are mild and resolve quickly once the source is removed. The real skill is knowing when it fits the typical pattern and when it does not.

If the horse is bright, eating, and improves after changing forage, it is usually straightforward. If there is any doubt, especially around swallowing or behavior, treat it as something more serious until proven otherwise. That is how you avoid missing the cases that truly matter.

If you are unsure whether your horse’s drooling is simple slobbers or something more serious, ASK A VET™ can help you assess the situation and decide what to do next with confidence.