Neely Heidorn | 6/17/2011 10:51:03 PM
Molly Culberson, DVM
One possible cause of equine epistaxis, or nosebleed, is a growth known as an ethmoid hematoma. An ethmoid hematoma is a benign, well-encapsulated mass that can originate from the ethmoid turbinates, or occasionally from the paranasal sinuses. The ethmoid turbinates are located at the back of each nasal passage, and is a very vascular tissue. The inciting cause of the hematoma is unknown, but it develops when hemorrhage or bleeding occurs in the soft tissues covering the turbinate or sinus, which expands the overlying tissue, forming the capsule of the mass. The mass can expand into the sinuses of the skull, including the frontal, sphenopalantine, maxillary, or nasal sinuses and can result in facial deformity. Although the direct cause is unknown, it is not caused by an infectious agent and cannot be spread from horse to horse.
Ethmoid hematomas are most commonly reported in middle-aged geldings, although can occur in both young horses and mares as well. The most common complaint or observation of owners is a mild, intermittent bilateral or unilateral epistaxis, or nosebleed. There may also be a respiratory noise associated with the mass if it is obstructing airflow due to location or size of the hematoma, malodorous breath, as well as a possible facial swelling and head shaking or reports of being head shy.
The most common method of diagnosis is based on clinical history, and results of upper airway endoscopy. The typical appearance of an ethmoid hematoma on endoscopy is a smooth glistening mass that can be yellow-green, mottled, or red-purple in color. Early lesions may appear as a small swelling or bruising on the surface. Radiographs are also often used to confirm the location and involvement of the mass. Different views can provide information such as sinus involvement, and if the mass extends past the nasal septum and invades the opposite nasal cavity. Biopsy and histopathology is an option for diagnosis, but is more often used in conjunction with surgical excision. Other less frequently used diagnostic methods include computed topography (CT), which eliminated the superimposition of radiographs and gives a clear image of size and extend of the lesion, and nuclear scintigraphy which also confirms the extent of the lesion. A diagnosis early in the progression of the mass is ideal because there is no prevention, and the rate of success is higher when treating small masses.
There are several options for treatment of ethmoid hematomas, including intra-lesional injections, trans-endoscopic use of a laser, and surgical resection. Intra-lesional injections of formaldehyde can be performed, but requires multiple treatments, and can occasionally have serious complications in some cases. Laser therapy directed through the use of an endoscope is often used in smaller lesions, as well as adjunctive therapy to surgical resection. Surgical resection is required for some cases, and can be performed in the standing, sedated horse for small masses, but most often under general anesthesia to allow for adequate visualization and surgical access. The most common complication associated with surgical resection is intra-operative hemorrhage which should be expected and prepared for. Multiple modes of treatment are often used in combination to reduce the rate of recurrence.
The prognosis for an untreated ethmoid hematoma is guarded to poor for survival. This type of mass is progressive and will expand in size, eventually obstructing the sinuses and nasal passage, resulting in an obstructed airway, and possibly obstructing the pharynx as well. This can be temporarily alleviated with a tracheotomy, but is not a permanent solution. The rate of recurrence varies from reported percentages from 20-50% based on choice of treatment. The recurrence rate with surgical removal in combination with laser excision has been reported as low as 20%.
If you would like to schedule an appointment with a veterinarian please contact:
Equine Health Studies Program
School of Veterinary Medicine
Louisiana State University
Baton Rouge, LA 70803