Guttural Pouch Infections in Horses: Nasal Discharge, Bleeding and Strangles Carrier Risk

By Dr Duncan Houston

Guttural pouch disease can look like a simple nasal discharge, but some cases can become life threatening fast.

The guttural pouches are small structures with a very big clinical reputation.

In many horses, guttural pouch disease shows up as nasal discharge, throatlatch swelling, fever, or a horse that seems to have never fully cleared strangles. In other horses, especially with guttural pouch mycosis, the first obvious sign may be a nosebleed. That matters because fungal disease can erode major arteries and cause sudden, severe, sometimes fatal bleeding.

This is why guttural pouch disease is not something to casually rinse, wait on, or guess about. The signs can be subtle, but the structures nearby are not forgiving: major arteries, cranial nerves, the airway, the pharynx, and the swallowing apparatus all sit dangerously close.

Quick Answer

Guttural pouch infections in horses most commonly include guttural pouch empyema, where pus accumulates in one or both guttural pouches, often after strangles, and guttural pouch mycosis, a fungal disease that can erode major arteries and cause life threatening nosebleeds. Endoscopy is usually the key diagnostic test because it allows the veterinarian to see pus, chondroids, fungal plaques, bleeding, and nerve related abnormalities directly. (MSD Veterinary Manual)

Call your veterinarian urgently if your horse has blood from the nose, repeated one sided nasal discharge, difficulty swallowing, feed or water coming from the nostrils, noisy breathing, facial asymmetry, throatlatch swelling, or signs of strangles that do not fully resolve.

What Are the Guttural Pouches?

The guttural pouches are paired air filled extensions of the auditory tubes. Each horse has one on each side of the head, located around the throatlatch region and connected to the pharynx. Each pouch is divided by the stylohyoid bone into a larger medial compartment and a smaller lateral compartment. (MDPI)

They matter because several critical structures run along or near their walls, including the internal carotid artery, external carotid artery, maxillary artery, and multiple cranial nerves involved in swallowing, facial expression, tongue function, airway control, and upper respiratory function. Disease in this area can therefore cause bleeding, nerve dysfunction, swallowing problems, airway obstruction, and neurological signs. (MDPI)

In practice, the guttural pouch is one of those places where anatomy makes a small infection potentially serious.

It is not just a pocket of pus or fungus.

It is a pocket of pus or fungus sitting beside some extremely important plumbing and wiring.

Why Guttural Pouch Disease Matters

Guttural pouch disease matters for three main reasons.

First, bacterial disease can become chronic. With guttural pouch empyema, pus can remain in the pouch and dry into firm balls called chondroids. These can allow a horse to look healthy while still harbouring and sometimes shedding Streptococcus equi, the bacteria that causes strangles. (AAEP)

Second, fungal disease can be catastrophic. With guttural pouch mycosis, fungal plaques often sit over major arteries. The fungus can erode through the artery wall, causing sudden, severe epistaxis, meaning bleeding from the nose. ACVS advises that any blood from one or both nostrils should be treated as an emergency. (American College of Veterinary Surgeons)

Third, the cranial nerves nearby can be damaged. This can cause difficulty swallowing, feed material coming from the nostrils, coughing during eating, facial asymmetry, laryngeal dysfunction, abnormal breathing noise, and aspiration pneumonia risk. (MSD Veterinary Manual)

That is the real clinical point: the discharge may be what the owner sees, but the danger is what may be happening deeper inside.

The Main Types of Guttural Pouch Disease

1. Guttural pouch empyema

Guttural pouch empyema means pus has accumulated inside one or both guttural pouches. It usually follows an upper respiratory bacterial infection, especially Streptococcus equi, the cause of strangles. Retropharyngeal lymph node abscesses can rupture into the guttural pouch and fill it with pus. (MSD Veterinary Manual)

Signs may include:

• Thick nasal discharge
• One sided or two sided purulent discharge
• Fever
• Depression
• Reduced appetite
• Painful swelling around the throatlatch or parotid area
• Enlarged lymph nodes
• Stiff head carriage
• Noisy breathing in severe cases
• Difficulty swallowing
• Persistent discharge after apparent strangles recovery

MSD Veterinary Manual lists intermittent purulent nasal discharge, painful parotid swelling, lymphadenopathy, fever, depression, anorexia, stiff head carriage, stertorous breathing, dysphagia, and neuropathy as possible signs of guttural pouch empyema. (MSD Veterinary Manual)

2. Chondroids and strangles carrier disease

When pus remains in the guttural pouch for long enough, it can dry and form chondroids. These are firm, inspissated balls of pus that can sit inside the pouch and keep infection going. AAEP notes that horses can have guttural pouch chondroids without obvious signs and may chronically shed bacteria while appearing outwardly healthy. (AAEP)

This is one of the biggest reasons strangles outbreaks recur.

The horse may look recovered.

The barn may relax.

The bacteria may still be sitting in the guttural pouch like a villain in a side room waiting for the sequel.

Cornell recommends endoscopic examination and washes of both guttural pouches in horses with positive PCR or culture, and three negative guttural pouch washes seven days apart over 21 days to confirm negative status in this testing pathway. (Cornell Vet College)

3. Guttural pouch mycosis

Guttural pouch mycosis is a fungal infection of one or both guttural pouches. It is rare, but it is the disease that makes vets immediately worry about sudden, fatal bleeding.

Fungal plaques most commonly involve major blood vessels, especially the internal carotid artery, and Aspergillus species are commonly associated. Over time, fungal damage can erode the arterial wall and cause severe haemorrhage. (MSD Veterinary Manual)

Signs may include:

• Blood from one or both nostrils
• Recurrent mild nosebleeds
• Sudden heavy nosebleed
• Difficulty swallowing
• Feed material coming from the nostrils
• Coughing while eating
• Choke like episodes
• Facial asymmetry
• Drooping eyelid or Horner syndrome signs
• Abnormal head posture
• Noisy breathing
• Throatlatch pain

ACVS states that several smaller nosebleeds may occur before a fatal episode and that any blood from one or both nostrils should be treated as an emergency. (American College of Veterinary Surgeons)

4. Other guttural pouch problems

Not every guttural pouch problem is a bacterial or fungal infection.

Other conditions include:

• Guttural pouch tympany, especially in foals
• Temporohyoid osteoarthropathy
• Trauma
• Masses or neoplasia
• Foreign body related disease
• Skull base injury
• Primary sinus or airway disease that mimics guttural pouch disease

A 2023 diagnostic imaging review lists empyema, tympany, mycosis, and temporohyoid osteoarthropathy among the common guttural pouch diseases, and notes that CT can be especially useful when disease involves surrounding structures. (MDPI)

Guttural Pouch Disease Risk Framework

The most important decision point is this: blood from the nose is not a wait and see sign in horses.

What Signs Should Horse Owners Watch For?

The signs depend on whether the problem is bacterial, fungal, mechanical, neurologic, or related to another disease.

Watch for:

• One sided nasal discharge
• Thick yellow or white discharge
• Discharge that returns after strangles
• Bad smell from the nose
• Blood from one or both nostrils
• Recurrent mild nosebleeds
• Painful throatlatch swelling
• Fever
• Depression
• Reduced appetite
• Difficulty swallowing
• Feed or water coming from the nostrils
• Recurrent choke like episodes
• Coughing when eating
• Noisy breathing
• Facial asymmetry
• Drooping eyelid or sunken eye on one side
• Head tilt or abnormal head carriage
• Weight loss from poor swallowing or chronic disease

The pattern matters.

Thick pus after strangles makes me think about empyema and carrier risk.

Blood makes me think about mycosis until proven otherwise.

Feed or water from the nostrils makes me worry about dysphagia, nerve damage, choke, or pharyngeal dysfunction.

When Is This an Emergency?

Call your veterinarian immediately if your horse has:

• Any blood from one or both nostrils
• Repeated mild nosebleeds
• Sudden heavy nosebleed
• Difficulty swallowing
• Feed or water coming from the nostrils
• Severe coughing while eating
• Noisy breathing
• Respiratory distress
• Facial paralysis or facial asymmetry
• Drooping eyelid, sunken eye, or abnormal sweating on one side
• Severe throatlatch swelling
• High fever with depression
• Sudden collapse or weakness
• Persistent nasal discharge after strangles
• A horse suspected of being a strangles carrier on a property with recurring cases

Guttural pouch mycosis is the major emergency concern because fatal haemorrhage can occur if an affected artery ruptures. MSD Veterinary Manual reports that guttural pouch mycosis is life threatening and can result in fatal haemorrhage in almost half of cases, while ACVS emphasises that any nasal bleeding should be treated as an emergency. (MSD Veterinary Manual)

Do not exercise, travel, or stress a horse with a suspected guttural pouch bleed.

Keep the horse quiet and call the vet.

How Do Vets Diagnose Guttural Pouch Disease?

Endoscopy

Endoscopy is the key diagnostic tool for many guttural pouch diseases. A flexible camera is passed through the nasal passage into the pharyngeal opening of the guttural pouch so the veterinarian can inspect both pouches directly.

Endoscopy can identify:

• Pus
• Fluid levels
• Chondroids
• Retropharyngeal abscess drainage
• Fungal plaques
• Blood clots
• Active bleeding
• Nerve related abnormalities
• Structural changes
• Tympany or pouch distortion

MSD Veterinary Manual lists endoscopic examination of both guttural pouches as a core diagnostic step for guttural pouch empyema, and ACVS describes endoscopy as the gold standard for diagnosing guttural pouch mycosis. (MSD Veterinary Manual)

PCR and culture

If strangles or bacterial infection is suspected, your vet may collect pus, guttural pouch lavage fluid, nasal or nasopharyngeal samples, or abscess material for PCR and culture.

PCR detects bacterial DNA, while culture attempts to grow live bacteria. Cornell notes that PCR can detect DNA from live, dead, or modified live vaccine origin bacteria, so results must be interpreted with timing, clinical signs, exposure history, and sometimes culture. (Cornell Vet College)

Radiographs

Radiographs can show fluid lines, masses of material, chondroids, retropharyngeal swelling, or airway compression. MSD Veterinary Manual notes that radiographs can identify fluid lines in the guttural pouch and associated retropharyngeal masses. (MSD Veterinary Manual)

CT

CT can be useful in complex or chronic cases, especially when surrounding structures, bones, the temporohyoid apparatus, skull base, or deep soft tissues need assessment. A 2023 imaging review notes that CT is increasingly available and can help assess surrounding soft tissue and bony lesions linked to guttural pouch disease. (MDPI)

What Else Can Look Like Guttural Pouch Disease?

Not every nasal discharge or nosebleed comes from the guttural pouch.

Important rule outs include:

• Strangles without guttural pouch involvement
• Sinusitis
• Dental root infection
• Tooth extraction complications
• Ethmoid haematoma
• Nasal trauma
• Foreign body in the nasal passage
• Nasal or sinus tumour
• Pneumonia
• Choke
• Equine influenza
• Equine herpesvirus
• Equine viral arteritis
• Temporohyoid osteoarthropathy
• Basilar skull trauma
• Coagulation disorders
• Exercise induced pulmonary haemorrhage in performance horses

The location and character of the discharge matter.

One sided thick discharge may point toward guttural pouch, sinus, or dental disease.

Blood may be guttural pouch mycosis, ethmoid haematoma, trauma, pulmonary bleeding, or other vascular disease.

Feed from the nostrils raises concern for choke, dysphagia, pharyngeal dysfunction, or nerve damage.

This is why endoscopy is so useful. It helps move the case from guessing to seeing.

How Is Guttural Pouch Empyema Treated?

Treatment depends on severity, whether strangles is involved, whether chondroids are present, and whether the horse is systemically unwell.

Treatment may include:

• Isolation if strangles is possible
• Endoscopic examination
• Repeated guttural pouch lavage
• Culture or PCR testing
• Topical antimicrobial therapy in selected cases
• Systemic antibiotics when indicated
• NSAIDs for fever, pain, and inflammation when appropriate
• Supportive care for sick horses
• Removal of chondroids
• Surgical drainage for large chondroid burden or unresolved abscessation

MSD Veterinary Manual states that systemic antimicrobials alone rarely resolve guttural pouch empyema and that repeated guttural pouch lavage is necessary. It also notes that chondroid material can act as a chronic infection source and may require endoscopic or surgical removal. (MSD Veterinary Manual)

The owner version is simple: this is not usually fixed by one course of antibiotics.

If there is pus or chondroids sitting inside the pouch, the pouch often needs to be physically flushed, cleared, and reassessed.

How Is Guttural Pouch Mycosis Treated?

Guttural pouch mycosis is treated very differently from bacterial empyema because the biggest risk is bleeding from an artery.

Treatment may include:

• Emergency stabilisation if bleeding is severe
• Blood transfusion in selected cases
• Endoscopy to identify fungal plaque and bleeding source
• Surgical occlusion of the affected artery
• Balloon catheter occlusion
• Transarterial coil or plug embolisation
• Topical or systemic antifungal treatment in selected cases
• Supportive care for nerve damage or swallowing problems
• Feeding support if dysphagia is present
• Airway surgery in selected cases

ACVS states that medical treatment with topical antifungals can be slow, may take months, and carries ongoing risk of fatal bleeding. Surgical options aim to block the affected artery, removing the risk of haemorrhage and often allowing fungal lesions to regress. (American College of Veterinary Surgeons)

MSD Veterinary Manual similarly states that arterial occlusion can be attempted with ligation, balloon catheter placement, or fluoroscopic guided transarterial coil embolism, primarily to decrease the risk of fatal haemorrhage. (MSD Veterinary Manual)

In practice, a mycosis case with bleeding is not a “try some antifungal and see” situation.

It is a surgical risk conversation.

Can Horses Recover?

Yes, many horses recover, but prognosis depends heavily on the disease type and how advanced it is.

Guttural pouch empyema often has a good prognosis when treated properly with lavage, infection control, chondroid removal when needed, and appropriate follow up. AAEP notes that prognosis for empyema is good with medical treatment, often involving lavage and antibiotic therapy. (AAEP)

Guttural pouch mycosis has a more guarded prognosis because of bleeding risk and nerve damage. ACVS notes that if a horse survives the bleeding episode and surgery is performed quickly, prognosis is usually good when bleeding is the only preoperative sign. However, nerve dysfunction can require prolonged aftercare, and recovery of nerve function may take 6 to 18 months or may not fully occur. (American College of Veterinary Surgeons)

Dysphagia is especially concerning because it can lead to aspiration pneumonia, poor nutrition, and prolonged recovery.

The earlier the problem is identified, the better the odds.

What Should You Do Right Now?

If your horse has thick nasal discharge

Check:

• Is it one sided or both nostrils?
• Is there fever?
• Is the horse dull?
• Is there throatlatch swelling?
• Has there been recent strangles exposure?
• Is the discharge persistent or recurring?

Isolate the horse if strangles is possible and contact your veterinarian.

If your horse has blood from the nose

Treat it as an emergency.

Do not exercise the horse.

Do not transport unless your vet advises it is safe.

Keep the horse quiet, reduce stress, and call your veterinarian immediately.

If your horse had strangles and still has discharge

Ask your vet whether guttural pouch endoscopy, lavage, PCR, or culture is needed.

Do not assume the horse is clear because the lymph nodes look better.

If your horse has difficulty swallowing

Remove feed until veterinary advice is received if there is obvious choking or aspiration risk.

Call your vet urgently, especially if feed or water is coming from the nostrils.

If your property keeps getting strangles

Carrier investigation is important.

UF IFAS notes that farms with recurring strangles cases should be investigated for asymptomatic carriers with endoscopic examination of the guttural pouches. (Ask IFAS - Powered by EDIS)

Common Mistakes With Guttural Pouch Disease

Mistake 1: Treating a nosebleed as minor

A small nosebleed can precede a fatal bleed in guttural pouch mycosis. Any blood from the nostril should be taken seriously. (American College of Veterinary Surgeons)

Mistake 2: Assuming strangles is over because the horse looks better

Carrier horses may appear healthy but continue to harbour S. equi in the guttural pouches and intermittently shed bacteria. (Ask IFAS - Powered by EDIS)

Mistake 3: Using antibiotics without confirming the problem

Systemic antibiotics alone rarely resolve guttural pouch empyema when pus or chondroids remain in the pouch. Lavage and sometimes chondroid removal are often needed. (MSD Veterinary Manual)

Mistake 4: Missing dysphagia

Feed from the nostrils, coughing during eating, or recurrent choke like episodes can indicate nerve dysfunction. In guttural pouch mycosis, dysphagia worsens prognosis. (MSD Veterinary Manual)

Mistake 5: Not isolating suspected strangles related cases

If S. equi is involved, the horse may be contagious. Movement and shared equipment can spread disease across a property.

Mistake 6: Waiting for discharge to become dramatic

Guttural pouch disease can be subtle. Persistent one sided discharge, mild recurrent bleeding, or a horse that never quite clears after strangles deserves investigation.

How To Reduce Guttural Pouch Infection Risk

Not all guttural pouch disease can be prevented, especially guttural pouch mycosis, where the cause is not always clear. But you can reduce the risk of bacterial disease and strangles carrier problems.

Practical prevention includes:

• Isolate horses with fever, nasal discharge, or swollen lymph nodes
• Quarantine new arrivals according to veterinary advice
• Use separate water buckets, feed tubs, and grooming gear during outbreaks
• Clean and disinfect shared equipment
• Avoid moving horses during suspected strangles outbreaks
• Test recovered strangles horses when carrier status is a concern
• Investigate recurring strangles cases for guttural pouch carriers
• Do not ignore persistent nasal discharge after respiratory disease
• Work with your vet on strangles vaccination and biosecurity decisions
• Keep accurate records of fever, discharge, testing, and recovery dates

Cornell advises careful sampling technique to avoid cross contamination and states that guttural pouch washes and PCR or culture testing are important in horses with positive results or carrier concerns. (Cornell Vet College)

Myth vs Reality

Frequently Asked Questions

Is guttural pouch disease contagious?

It depends on the cause. Guttural pouch mycosis is not typically contagious between horses. Strangles related guttural pouch empyema or carrier disease can be contagious because horses may shed Streptococcus equi. (AAEP)

What is the first sign of guttural pouch mycosis?

The most common sign owners notice is a moderate to severe nosebleed, although smaller nosebleeds may occur first. Other signs can include difficulty swallowing, feed from the nostrils, facial asymmetry, abnormal breathing noise, or throatlatch pain. (American College of Veterinary Surgeons)

Can guttural pouch empyema go away on its own?

Mild cases may fluctuate, but persistent pus, chondroids, or strangles carrier disease usually needs veterinary treatment. MSD Veterinary Manual states that systemic antimicrobials alone rarely resolve guttural pouch empyema and that repeated lavage is necessary. (MSD Veterinary Manual)

How do vets check for a strangles carrier?

The most useful approach is usually guttural pouch endoscopy with lavage for PCR and culture. Cornell notes that endoscopic examination and washes of both guttural pouches should be performed in horses with positive PCR or culture, and repeated negative washes may be used to confirm negative status. (Cornell Vet College)

Can a horse survive guttural pouch mycosis?

Yes, especially if bleeding is recognised early and surgical treatment is performed quickly. Prognosis is more guarded if severe haemorrhage, dysphagia, airway dysfunction, or nerve damage has already occurred. (American College of Veterinary Surgeons)

The Bottom Line

Guttural pouch disease is one of those equine problems where the external sign can look deceptively simple.

A bit of discharge.

A mild nosebleed.

A horse that had strangles but never quite cleared.

A choke like episode that seems random.

But inside the guttural pouch, the stakes can be much higher. Bacterial pus can create chronic infection and strangles carrier disease. Chondroids can keep a property trapped in recurring outbreaks. Fungal plaques can damage major arteries and cause fatal bleeding. Nerve involvement can affect swallowing, breathing, and long term recovery.

If your horse has thick persistent nasal discharge, recent strangles history, throatlatch swelling, difficulty swallowing, feed from the nostrils, or any blood from the nose, do not guess.

Get the guttural pouch looked at.

Early endoscopy can be the difference between a manageable infection and a dangerous emergency.

If you are unsure whether your horse’s nasal discharge, nosebleed, swallowing problem, or strangles recovery could involve the guttural pouch, ASK A VET™ can help you organise the signs, track the timeline, and decide when veterinary care should not wait.