Nosebleed (Epistaxis) in Horses

Key takeaways

Nosebleeds (epistaxis) are common in horses, and may stem from infections, cancers, foreign objects, injuries, or exercise-induced pulmonary hemorrhage. 

  • Nosebleeds may present acutely or chronically, and range from drops of blood falling from one nostril to a stream of blood from both
  • Mild nosebleeds that do not recur do not typically require treatment, however a heavier flow or repeated nosebleeds may suggest a more serious underlying condition
  • Diagnostics include a physical examination, blood tests, endoscopy, and examination of respiratory tract samples
  • Treatment varies depending on the underlying condition
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A closer look: Nosebleed (Epistaxis) in Horses

Nosebleeds are common in horses. The severity of a nosebleed depends on how frequently it occurs and the amount of blood lost. A single nosebleed with a small amount of blood loss is generally not of medical concern. Some conditions, such as guttural pouch mycosis, can lead to significant blood loss, and may be fatal. Horses with a consistent nosebleed, repeated episodes of nosebleeds, or losing large amounts of blood require immediate medical attention.

Possible causes

Nosebleeds in horses may be caused by conditions affecting both upper or lower airways.

Nosebleeds may also be idiopathic, without an obvious cause.

Risk factors

Thoroughbreds and older horses are more susceptible to nosebleeds.

Nosebleeds may be chronic or acute, consistent or inconsistent, and have a light or heavy flow depending on the underlying condition. The position of a horse’s head may also influence blood flow.

Horses are more likely to bleed out of one nostril if the upper respiratory tract is affected, or both if the lower tract is affected.

An underlying condition such as GPM may result in profound blood loss indicating arterial damage, which differs from trickles of blood associated with a minor injury.

Testing and diagnosis

Diagnostics include

  • Physical examination
  • Diagnostic imaging, including skull X-rays or ultrasound of the lungs
  • Bronchoalveolar lavage (rinsing the lungs and testing the fluid)
  • Transtracheal washes (rinsing the throat)
  • Endoscopy
  • Biopsy
  • Bloodwork

Treatment depends on the underlying cause, and may include surgery, radiation therapy, antibiotics, or sinus draining. Recurrent treatment and multiple follow-up appointments to track recovery may be necessary.

Similar symptoms

Nosebleeds may be mistaken for other nasal discharge. Horses that have injuries elsewhere on their body may rub or itch the injury with their nose, resulting in blood spots that may resemble a nosebleed.

Associated symptoms

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