Finding your horse with a nosebleed can be a scary sight. Among the many causes are odd masses called ethmoid hematomas [hē-ma-TŌ-mahs].
These masses grow for unknown reasons in a horse’s nasal cavity and connected sinuses. Although they look and grow like tumors, these masses are not cancerous. But they still cause problems as they enlarge and press on nearby structures.
An ethmoid hematoma usually causes intermittent bleeding from the nostril on the same side. With larger masses, airflow can be blocked and your horse can have trouble breathing.
Ethmoid hematomas can usually be seen through an endoscope. The surgical treatment used most often was developed by a surgeon at the University of Florida Large Animal Hospital and can usually be performed in a standing horse.
If your horse has a nosebleed, contact your veterinarian to help pinpoint the cause.