Nosebleeds in horses can look pretty alarming, whether it’s just a trickle or a full-on flow. Thankfully, there are a few common reasons for horses to experience epistaxis, or a bloody nose. While most cases are not serious, it’s worthwhile to investigate the underlying cause and know when to see your veterinarian. Here’s what you should keep in mind when your horse bleeds from their nose.

Nosebleeds in Horses from Trauma
The most common reason horses get nosebleeds is from an acute injury. The blood vessels inside the nose are tiny and delicate, and will bleed if your horse bumps into a gate, scratches a bug bite in or around their nose, or gets kicked by another horse. In this case, you’ll generally see a small amount of blood from one or both nostrils, and the bleeding normally subsides within fifteen minutes.

Nosebleeds after Intense Exercise
Another very common cause of nosebleeds in horses is exercise‐induced pulmonary hemorrhage (EIPH). Mostly seen in racing thoroughbreds after intense exercise, EIPH occurs when blood enters the lungs, possibly due to a ruptured blood vessel from increased heart rate and blood pressure, deep breathing, and intense movements associated with heavy exercise.
EIPH is incredibly common, observed via endoscope in as many as 75% of horses after intense exercise. Only a small percentage of horses with EIPH will experience external bleeding from their nose. EIPH is not a serious condition, but it is progressive and can affect racing performance as it worsens.
Your veterinarian will need to confirm the diagnosis, and may prescribe Furosemide, a diuretic that has been shown in research studies to be effective treatment for EIPH. You might also see results with a nasal strip, which reduces resistance in the nasal passages for less pressure associated with EIPH.

When To Call Your Vet About Nosebleeds In Horses
While nosebleeds are usually not serious, in some cases they are a sign that your horse needs veterinary attention. Any time your horse has a nosebleed, or any other concerning symptom, take their vital signs. Unexpected changes in your horse’s heart rate, temperature, or breathing can indicate distress.
Many causes of nosebleeds are not an emergency, but you should still call your veterinarian during their soonest office hours. Any instance of bleeding that occurs without explanation should be investigated. Your horse could have anything from a sinus infection, to an embedded foreign body like a pebble, a tumor, or a polyp in the nasal cavity or lower respiratory system.
If the nosebleed occurs for more than 20 minutes, or seems especially severe, call your veterinarian right away. Regardless of the underlying cause, extreme blood loss can be fatal. One of the more serious, though rare causes of a nosebleed is a guttural pouch infection that has begun to break down the blood vessels, especially carotid artery that runs along the wall of the guttural pouch. In early stages, this condition causes nasal discharge and difficulty swallowing, but if left untreated, it will result in a severe, fatal nosebleed.
A nosebleed can consist of bright red blood, which signals it’s a fresh bleed, though you could also see dark, clotted blood, blood-tinged mucus, or a mix of blood and mucus. You may see unilateral (one-sided) bleeding, or bleeding from both nostrils. It’s important that you describe your horse’s symptoms to your veterinarian accurately to help them rule out possible causes.