Racehorse Nosebleeds: EIPH, Treatments & What to Do

Last updated: March 6, 2025

By: Miles HenryFact Checked

Seeing blood flowing from your horse’s nose after a race can be alarming. In racehorses, nosebleeds (epistaxis) often signal underlying conditions like Exercise-Induced Pulmonary Hemorrhage (EIPH), a common but serious issue.

I’ve seen this firsthand. One of my Thoroughbreds developed EIPH, and managing it required veterinary intervention, adjustments in training, and preventive care. Ignoring a nosebleed can lead to long-term respiratory damage, reduced performance, and even disqualification from racing.

This guide breaks down the causes, treatments, and prevention strategies for racehorse nosebleeds, blending scientific research with my years of experience training and racing horses. Whether you’re an owner, trainer, or racing enthusiast, you’ll gain practical knowledge to protect your horse’s health and performance.

Common Causes of Nosebleeds in Racehorses

Nosebleeds (epistaxis) in racehorses range from mild irritation to serious health concerns. Because horses are obligate nasal breathers—they cannot breathe through their mouths—any respiratory issue can significantly impact their performance and well-being. (Differential diagnosis of epistaxis in the horse).

1. External Causes of Nosebleeds

✅ Trauma or Injury – Head injuries, blows to the nasal passage, or accidents at the starting gate can cause bleeding.
✅ Foreign Objects – Inhalation of dust, hay particles, or other debris can irritate the nasal passages, potentially leading to nosebleeds.
✅ Environmental Factors – Poor ventilation, dust, mold, and ammonia buildup in stalls can trigger respiratory irritation and nosebleeds.

2. Medical Conditions Leading to Nosebleeds

🔹 Exercise-induced pulmonary Hemorrhage (EIPH)
Exercise-induced pulmonary hemorrhage (EIPH) involves bleeding within the lungs during intense exercise. Studies indicate that a significant percentage of racehorses experience EIPH to varying degrees, leading to reduced oxygen intake, impaired recovery, and, in severe cases, life-threatening hemorrhaging. (Quantification of exercise-induced pulmonary haemorrhage).

✅ Risk Factors:

• Cold temperatures
• Frequent racing with short recovery time
• Older horses with lung stress
• Sprint races with high pulmonary pressure

✅ Symptoms:

• Post-race coughing or labored breathing
• Reduced performance and early fatigue
• There is blood at the nostrils following intense exercise.

🔹 Sinusitis & Respiratory Infections
Bacterial or viral infections, including Equine Influenza Virus (EIV) and Equine Herpesvirus (EHV), can weaken blood vessels in the sinuses, leading to nosebleeds.

✅ Symptoms:

• Nasal discharge (often foul-smelling)
• Fever and swelling around the sinuses
• Recurring low-grade nosebleeds

🔹 Guttural Pouch Mycosis (GPM)
A fungal infection in the guttural pouches can erode major blood vessels, leading to severe, potentially fatal bleeding (Guttural pouch mycosis in horses).

🚨 Emergency Alert: A mild, seemingly harmless nosebleed can be the first warning sign of Guttural Pouch Mycosis (GPM). If untreated, a second hemorrhage could be massive and fatal. Seek veterinary care immediately if bright red blood appears and does not stop quickly.

🔹 Blood Clotting Disorders
Some horses experience nosebleeds due to coagulopathies or clotting disorders. These may be genetic or linked to diet deficiencies.

💬 Personal Experience: One of my young horses had excessive bleeding from minor scrapes. A blood test confirmed a platelet deficiency, which we managed with diet changes and close monitoring.

🩺 When to Call the Vet

Before seeking veterinary care, assess:
✅ Frequency – Is this a one-time event, or does it happen after every race?
✅ Duration – Does the bleeding stop within 15 minutes, or is it prolonged?
✅ Severity – Is it a trickle or a steady flow? Heavy bleeding may indicate vascular damage.

For more on equine respiratory health, see Feeding a Horse With Heaves and Horse Hay Alternatives.

🔬 Diagnosing Nosebleeds in Horses

A single nosebleed may not always be a cause for alarm, but frequent or heavy bleeding can indicate a more serious issue. Proper diagnosis helps identify whether the cause is trauma, a respiratory condition, or an underlying disease.

🔍 Key Observations Before Calling the Vet

Before seeking veterinary care, assess the severity and frequency of the nosebleed using the following criteria:

✅ How often does the horse bleed? – Recurring episodes may indicate a chronic condition like EIPH or sinusitis.
✅ How long does each episode last? – If bleeding continues for more than 15 minutes, seek veterinary attention.
✅ How much blood is lost? – Heavy bleeding (steady flow or pooling) suggests a serious issue, like guttural pouch mycosis or a vascular injury.

💬 Personal Experience: I once had a barrel horse that bled slightly after an intense training session. At first, I thought it was just a one-time irritation, but after the third occurrence, I knew something wasn’t right. My vet performed an endoscopic exam and confirmed mild EIPH, which we managed through adjusted training and veterinary care.

🔹 Call your vet if bleeding lasts over 15 minutes or is accompanied by signs such as difficulty breathing.

🩺 Veterinary Diagnostic Methods

Once you’ve assessed your horse’s symptoms, the next step is a veterinary examination to determine the underlying cause. Here are the common diagnostic tools used by veterinarians:

🔬 Endoscopic Examination – A flexible camera is inserted into the nasal passage to check for:

• Bleeding sources (lungs vs. nasal passage)
• Signs of EIPH (lung capillary rupture)
• Tumors or polyps
• Fungal infections (Guttural Pouch Mycosis)

📸 X-rays, CT & MRI Scans – Used to detect abnormalities, such as:

• Sinus infections or inflammation
• Nasal fractures or trauma damage
• Tumors or polyps obstructing the airway

🧪 Bronchoalveolar Lavage (BAL) – This test helps determine if blood originates from the lungs by collecting fluid from the lower airways. It’s commonly used for diagnosing EIPH.

🩸 Blood Tests & Laboratory Analysis – Identifies systemic issues:

• Complete Blood Count (CBC) – Detects anemia, infections, or inflammation.
• Clotting Factor Tests – Screens for coagulopathies (e.g., thrombocytopenia or DIC).

Key Takeaway:

If your horse experiences frequent, prolonged, or heavy nosebleeds, a veterinary evaluation is necessary to rule out:
✅ Respiratory conditions (EIPH, infections, sinusitis)
✅ Fungal or bacterial infections (Guttural Pouch Mycosis)
✅ Trauma-related bleeding (fractures, head injuries)
✅ Underlying clotting disorders

💡 Proactive management and early diagnosis ensure your horse stays healthy and competitive.

How to Treat a Horse’s Nosebleed: Effective Solutions

Managing a racehorse’s nosebleed requires quick first aid, appropriate medical intervention, and long-term prevention strategies. While some nosebleeds are minor, persistent or heavy bleeding can signal serious health issues that require veterinary care.

🆘 First Aid for Horse Nosebleeds: What to Do Right Away

If your horse experiences a nosebleed, stay calm and follow these initial steps:

✅ Stay Calm – Panicking can stress the horse, raising blood pressure and worsening bleeding. Keep the horse in a quiet area to prevent unnecessary movement.

✅ Apply a Cold Compress – Place a damp, cool towel or ice pack wrapped in a cloth just below the eyes. This can help reduce blood flow to the nasal area.

✅ Do Not Insert Objects into the Nostrils – Unlike humans, horses cannot breathe through their mouths, so blocking the nostrils can restrict airflow and make breathing difficult.

✅ Call a Vet if Bleeding Persists Over 15 Minutes – If the bleeding does not slow down or stops and then starts again, consult a veterinarian. Chronic or severe nosebleeds require a thorough examination.

💬 Personal Experience: I once had a horse that developed a sudden, severe nosebleed after a morning gallop. I initially thought it was a minor irritation, but when it lasted over 10 minutes, I called my vet. An endoscopic exam later confirmed mild EIPH, prompting us to adjust the horse’s training and management plan.

💊 Medical Treatment for Nosebleeds: Lasix & Other Options

Once a vet assesses the condition, treatment options may include:

🔹 Lasix (Furosemide) – A diuretic commonly used for EIPH to reduce pulmonary blood pressure. While effective, it is controversial due to performance-enhancing concerns and restrictions in some jurisdictions (The Benefits of Lasix for Exercise-Induced Pulmonary Hemorrhage).

• 💊 Lasix: Effective or Overused?
  Lasix (Furosemide) is the most common treatment for EIPH, but it’s highly debated.
  ✅ Pros: Reduces pulmonary blood pressure, helping horses prone to EIPH perform better.
  ❌ Cons: Causes rapid dehydration, leading to weight loss that may give horses a performance advantage beyond treating EIPH.
  ❌ Regulatory Issues: Some racing jurisdictions ban or restrict Lasix due to concerns over potential abuse.

Key Debate: Some trainers argue that Lasix prevents suffering in horses that would otherwise bleed during races, while critics believe its widespread use may mask genetic predisposition to bleeding.

💬 Personal Experience:
For my horses racing on Lasix, the track veterinarian always administers the medication on race day, usually about three hours before the scheduled race time. Officials carefully document dosage and timing to comply with regulations.

🔹 Antibiotics – If the cause is bacterial sinusitis or another infection, antibiotics help eliminate underlying inflammation and reduce bleeding.

🔹 Surgical Interventions – Required for:

• Severe sinusitis (when chronic infections block normal drainage).
• Tumors or nasal polyps obstructing airflow.
• Guttural Pouch Mycosis (GPM) – This fungal infection can erode major blood vessels, requiring immediate surgical intervention to prevent fatal hemorrhaging.

🌿 Holistic Therapies for Nosebleeds

Expanding treatment options beyond Lasix, holistic and emerging therapies offer alternative support for respiratory health. While research is still developing, some horse owners and trainers report benefits when used alongside veterinary care and stable management.

🌀 Acupuncture & Chiropractic Adjustments

• Some trainers observe fewer EIPH episodes with acupuncture, which may help regulate blood flow and reduce lung inflammation.
• Chiropractic care could improve circulation and respiratory function, but scientific backing remains limited. (Alternative Equine Therapies).

🌿 Herbal Supplements

• Natural anti-inflammatories like Boswellia and Curcumin may help reduce lung inflammation.
• Mullein and Marshmallow Root are used for lung support, though their effectiveness for EIPH is debated. (The effect of herbal supplementation on the severity of exercise-induced pulmonary haemorrhage).

🧬 Stem Cell Therapy: The Future of Lung Repair?

• Potential Benefits: Preliminary cases have shown that adipose-derived stem cell therapy might help limit lung tissue damage and reduce the severity of EIPH, though more research is needed to confirm these findings. ​VetStem

🌊 Hyperbaric Oxygen Therapy (HBOT)

• High-pressure oxygen exposure may reduce inflammation and promote lung healing.
• Already used for laminitis and soft tissue injuries, it’s gaining attention for EIPH treatment.
• HBOT has been used as an adjunctive treatment for various equine conditions, including laminitis and soft tissue injuries, it’s gaining attention for EIPH treatment.. ​fvma.org

Key Takeaways

✔️ Alternative therapies may aid respiratory health but require more research.
✔️ Veterinary oversight is essential—these should complement, not replace, conventional treatments.
✔️ Best results come from a combined approach, including stable management, conditioning, and proper nutrition.

🩺 Treatment Options for EIPH and Nosebleeds

Treatment	How It Works	Pros	Cons
Lasix (Furosemide)	Reduces blood pressure in lungs	Effective for EIPH	Can cause dehydration, banned in some races
Nasal Strips	Opens nasal passages, reducing inhalation resistance	Drug-free, improves airflow	Less effective in severe cases
Acupuncture	May reduce stress-related bleeding	Holistic, minimal side effects	Limited scientific backing

🛠 How to Prevent Nosebleeds in Racehorses: Practical Strategies

While stable management, nutrition, and training adjustments can reduce respiratory stress, no method fully prevents nosebleeds in EIPH-prone horses. Regular veterinary monitoring is crucial for early detection and management. The following strategies can help minimize risk and improve respiratory health.

1. Stable & Air Quality Management

✅ Improve Ventilation – Ensure adequate airflow to reduce ammonia and dust, which trigger respiratory irritation. Proper stall ventilation lowers inflammation risks.
✅ Switch to Low-Dust Bedding – Pelleted or shredded paper bedding minimizes airborne particles that can irritate nasal passages.
✅ Soak Hay Before Feeding – Dampening hay reduces dust exposure, benefiting horses with sensitive airways or EIPH risk.

2. Training Modifications

✅ Gradual Conditioning – Horses prone to EIPH benefit from progressive fitness routines that reduce lung capillary stress.
✅ Monitor Workload – Limit high-intensity workouts and ensure adequate recovery.

3. Diet & Nutritional Support

✅ Omega-3 Fatty Acids (Flaxseed, Fish Oil) – Helps reduce lung inflammation and support vascular health.
✅ Antioxidants (Vitamin C & E) – Aids in tissue repair and minimizes oxidative stress.
✅ Vitamin K – Supports blood clotting in horses with coagulation issues.

4. Regular Veterinary Monitoring

✅ Routine Endoscopic Exams – Helps detect early signs of lung stress or minor hemorrhaging before it worsens.
✅ Post-Race Evaluations – Observe breathing patterns and check for delayed bleeding even after a normal finish.
✅ Diagnostic Imaging (X-rays, CT Scans) – Essential for ruling out sinusitis, guttural pouch mycosis, or polyps that could contribute to bleeding.

5. 📊 High-Tech Monitoring: Spotting EIPH Risks Early

Devices like EQUIMETRE and respiratory monitors can help identify early signs of pulmonary stress. These tools measure:
✅ Oxygen levels – Detects lung efficiency before a horse shows symptoms.
✅ Heart rate variability (HRV) – Can indicate lung strain during intense exercise.
✅ Real-time performance tracking – Helps trainers adjust workloads before nosebleeds occur.

6. 🧬 Breeding Considerations: Can We Reduce EIPH Genetically?

Some research suggests that EIPH may have a hereditary component, with certain bloodlines more prone to pulmonary hemorrhage.

✅ Breeders and racing organizations are now exploring selective breeding to reduce EIPH incidence.
✅ In jurisdictions where Lasix is banned, horses that can race without medication are highly valued.
✅ Future genetic screening may help identify EIPH-prone horses before they ever race.

Key Takeaway:

🏇 Preventing nosebleeds starts with proactive care. Stable management, fitness conditioning, and proper nutrition can significantly reduce risks. If your horse is prone to EIPH or sinus issues, take steps today to improve ventilation, adjust training, and support lung health.

📌 Want to optimize your stable for better respiratory health? Explore our guide on the best stall bedding options.

Real Cases: How Owners Manage Racehorse Nosebleeds

📌 Case Study 1: Thoroughbred with Recurrent EIPH

• Scenario: One of my Thoroughbreds developed frequent post-race nosebleeds, raising concerns about his long-term racing potential.
• Investigation: A veterinary endoscopic exam confirmed Exercise-Induced Pulmonary Hemorrhage (EIPH), which affects 60-95% of racehorses.
• Treatment:
  • Introduced Lasix (Furosemide) to reduce pulmonary pressure.
  • Adjusted training intensity to minimize lung stress.
  • Focused on better stable air quality and dietary adjustments (omega-3s, antioxidants).
• Outcome: The horse’s incidents of nosebleeds were reduced, allowing him to continue racing competitively.

🔹 Authority Source: According to a study by Murli Manohar & Thomas Goetz, EIPH presence doesn’t always correlate with higher pulmonary vascular pressures, suggesting that multiple factors—not just lung stress—contribute to the condition.

📌 Case Study 2: Pony with Chronic Sinusitis

• Scenario: A pony experienced persistent nosebleeds from one nostril, often after eating or during exercise.
• Investigation: X-rays and a sinus endoscopy revealed sinus inflammation due to an underlying dental infection.
• Treatment:
  • Dental surgery to remove the infected tooth.
  • Antibiotic therapy to clear up secondary infection.
• Outcome: The pony fully recovered with no further episodes of nosebleeds.

🔹 Key Insight: Nasal bleeding isn’t always linked to the lungs—sinus infections, dental disease, or guttural pouch issues can all be contributing factors.

🔹 Authority Source: A study on Guttural Pouch Mycosis highlights that fungal infections in this region can lead to life-threatening arterial hemorrhages, making early detection critical.

📖 What Science Says About Nosebleeds in Racehorses

📌 Veterinary Perspectives

• Jonathan Wood, Veterinary Surgeons: “Nosebleeds are often alarming due to the rich blood supply in equine nasal passages, but many cases resolve within 15 minutes without intervention.”
• Dr. Manohar, Iowa State University: “If 80% of animals in a given population have a condition, it may be considered ‘normal’—but that doesn’t mean it isn’t affecting performance.”

📌 Equine Science & Management

• Rutgers Equine Science Center: “Even minor nasal bleeds can look severe because of the number of blood vessels in a horse’s nasal passages. Owners should assess frequency and duration before panicking.”

Key Takeaway

✅ Real-life cases show how early detection, veterinary diagnostics, and tailored management strategies can significantly reduce the impact of nosebleeds on performance horses.
✅ Scientific research and expert opinions reinforce best practices in recognizing and managing EIPH, sinusitis, and clotting disorders.
✅ A combination of veterinary care, training adjustments, and stable management can help reduce future episodes.

Racehorse Nosebleeds: FAQs About EIPH & Treatment

Conclusion: Racehorse Nosebleeds

Managing nosebleeds in racehorses requires proactive care, early detection, and veterinary intervention. Whether caused by EIPH, sinus infections, trauma, or clotting disorders, understanding the underlying cause is crucial for effective treatment and prevention.

🔹 What’s Next?
✅ If your horse has a nosebleed, don’t wait—consult your veterinarian for a proper diagnosis.
✅ Evaluate your stable management & nutrition plan to minimize respiratory stress.
✅ Stay informed & proactive—routine exams and minor adjustments can prevent major health issues.
✅ Have experience with nosebleeds in your horse? Share your story in the comments—your insight could help other horse owners facing similar challenges.
✅ Found this guide helpful? Share it with fellow horse owners to spread awareness and promote better equine health!

💬 Let’s keep the conversation going! Have you dealt with a horse that suffered from EIPH or another condition leading to nosebleeds? How did you manage it? Share your experiences in the comments!