Although nosebleeds can look alarming, in most cases they are not serious. Even a small bleed can look dramatic, especially down the front of a grey horse. Most minor nosebleeds stop bleeding within 15min.

Is it serious?

  • How much blood is there? Would the drips slowly fill a teacup or rapidly overflow a bucket? If a Thoroughbred-sized horse loses more than about four litres (say half a big bucket) of blood rapidly, it needs emergency investigation
  • Is the blood coming from one nostril or two? A true nosebleed originating from within the head will only emerge from one nostril. A horse bleeding internally from the lungs will bleed from both nostrils
  • Is there any obvious reason for the bleeding? A horse may have just knocked its head, had a fall or the vet has just passed a stomach tube up the nose
  • Is it a one-off nosebleed? This may be a minor bleed that hopefully will not recur. Has it happened repeatedly? This is more serious and definitely needs investigation
  • Has the horse just been exercising hard? If so is more likely to have an exercise-induced pulmonary haemorrhage, when the blood originates from the lungs.

Common causes

Horses do not tend to have spontaneous nosebleeds, so there has to be a reason why it has happened.

A nosebleed — properly termed epistaxis — occurs when any part of the nasal passages (which are richly supplied with blood vessels), throat, lower airways or lungs are injured to such a degree that blood vessels are damaged and blood leaks out.

The commonest cause is a simple knock on the head, when alarmingly large amounts of blood may pour from one nostril. Such traumatic nosebleeds are usually self-limiting, but always consult your vet.

Nosebleed are also common reason if the delicate nasal tissues are knocked inadvertently when a vet passes a stomach tube up from the nostril. Sometimes this is inevitable, particularly if the horse moves at the wrong moment, but the bleeding always stops.

A moderate nosebleed, if accompanied by coughing, suggests a foreign body wedged in the nose or throat.

Occasionally tumours somewhere in the respiratory tract or inflammation of the sinuses (sinusitis) will produce a trickle of blood from the nose.

More serious problems include a progressive ethmoid haematoma, which is a lump that can grow inside the horse’s nose. It is similar to a giant blood blister and is aptly described as a “bleeding polyp”. It is a rare condition seen in around one horse in 2,500.

Guttural pouch mycosis is the typical cause of repeated nosebleeds, unrelated to exercise or trauma, and is a serious condition that requires surgery to control the bleeding.

Bleeding from both nostrils after exercise is most commonly due to an exercise-induced pulmonary haemorrhage. This happens when bleeding occurs from the blood vessels within the lung. Because the blood is coming up from the lungs, technically it is not a true nosebleed at all.

First aid for nosebleeds

  • With any nosebleed, the horse should be kept as calm as possible
  • The nose should never be packed, because horses breathe through their noses
  • It may help to hold an ice pack or cold wet towel just below the horse’s eyes. If the bleeding is coming from inside the nose area, this may reduce it
  • Horses have large volumes of blood inside them, so what looks like a lot coming out of the nose may not be critical for the horse. Even so nosebleeds should not continue for more than 15min; if one does, your vet should be consulted as an emergency
  • It may help your vet if you can say if the bleeding is coming from one nostril or both
  • There are some serious, but rare, conditions in the horse, which start as tiny nosebleeds that then get worse. A significant or recurrent nosebleed should always be checked out promptly.