Page 704 - The Veterinary Care of the Horse

A nosebleed 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
VetBooks.ir are damaged and blood leaks out. Possible causes include the following.
•
A simple knock on the head may cause blood to pour from one nostril. These nosebleeds
usually stop within fifteen minutes.

• Passage of a stomach tube may cause a nosebleed if the delicate nasal tissues are
inadvertently knocked, e.g. if the horse moves at the wrong moment. The flow of blood

can appear alarming but again the bleeding usually stops within 10–15 minutes.

More serious causes of nosebleeds are listed below.
• Guttural pouch mycosis. This is a condition that may cause severe nosebleeds unrelated

to exercise or trauma. It is unusual for the horse to die as a result of the first nosebleed

associated with this, but more than 50% will succumb, usually within days or weeks if
they do not receive the appropriate surgical treatment to control the bleeding. The
diagnosis and treatment of this disease is discussed in more detail on pages 454–5.

• Progressive ethmoid haematoma. This is a growth that develops on the tissues at the back

of the horse’s nose, sometimes within the sinuses. One of the first signs is a unilateral
(one-sided) blood-tinged nasal discharge, but as it enlarges it may obstruct the airflow
and cause abnormal respiratory noise, facial swelling and neurological signs. The

condition is diagnosed by endoscopy and sometimes radiography. The treatment options
include surgical excision, laser treatment, injection with formalin or freezing with liquid

nitrogen. The recurrence rate following surgery is around 25%. Fortunately the condition
is rare.

• Exercise-induced pulmonary haemorrhage (EIPH). This occurs when the tiny thin-walled

blood vessels in the lungs are damaged by the high pressures that develop within the
lungs of the galloping horse. Bleeding is sometimes seen at both nostrils and may be
accompanied by coughing and poor exercise performance. The bleeding may remain

within the airways rather than appear at the nostrils and require endoscopy to detect it. It
varies from slight to severe but is only very rarely fatal. Affected horses are sometimes

known as ‘bleeders’ or described as having ‘burst a blood vessel’. The condition is
described in more detail on pages 466–7.

Less common causes of nosebleeds include:

• a foreign body wedged in the nose or throat
• inflammation/infection of the sinuses