Fungal Plaque in a Horse

A 7 year-old gelding presented to PHD veterinary services for the complaint of mild epistaxis (bloody nasal discharge). Endoscopic exam of the nasal passages identified a golden colored mass (Figure 1) that was covered in blood and was located within the opening to the ethmoid turbinates. The mass was diagnosed as an ethmoid hematoma based on location, appearance, and behavior. The client was given the option of surgical removal or treatment with intra-lesional doses of formalin. Based on the relatively small size of the ethmoid hematoma it was decided to attempt treating 1-2x with formalin and if there was not complete resolution then surgical resection would be pursued.

Figure 1

Four weeks after the first injection of formalin, a follow-up endoscopy noted significant reduction in the size of the ethmoid hematoma (Figure 2) and what appeared to be a second mass deeper within the ethmoid turbinates. The second ethmoid hematoma was not visualized during the initial exam because the first ethmoid hematoma was blocking the view! Based on these findings, the second ethmoid hematoma was injected with formalin in a similar fashion as the original ethmoid hematoma.

Figure 2

Six weeks after the second formalin injection the client reported that there was a slight yet persistent bloody discharge from the affected nares. Endoscopic exam revealed what appears to be a fungal plaque (black/white/yellow) adhered to the site of the ethmoid hematoma (Figure 3 and 4). This is an unusual finding and may prove to be a challenging complication. Fungal plaques have a predilection for vascular tissue and can infect the upper airway of horses. Fungal infection within the guttural pouch of a horse is well documented and can result in a catastrophic hemorrhage if not diagnosed and treated early. Fungal infection within the ethmoid turbinates is not common in my experience. Often these fungal plaques do NOT respond to systemic anti-fungal medication and must be either removed or treated aggressively with topical medication.
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Figure 3

Figure 4

The current clinical plan for this horse is medication with oral anti-fungal medication for several weeks. If there is no change, the fungal plaques will be treated with topical anti-fungal medication. Stay tuned....

Finally after 4 weeks of anti-fungal medication, there is no evidence of a fungal plaque and there is NO evidence of an ethmoid hematoma (Figure 5). The ethmoid turbinates are visible for the first time in this horse since the initial exam. Although there is no evidence of an existing ethmoid hematoma, these tumors commonly reoccur hence the gelding will be monitored closely for the next 12 months. 

Figure 5

Ethmoid Hematoma versus Paranasal Sinus Cyst in a Horse

Two horses presented to PHD Veterinary services for the same complaint of "no air moving through one of the horse's nasal passages!" Both horses had a history of mild to moderate nasal discharge that had increased slowly over the past 6 months. On presentation, a simple evaluation of air passing through the nasal cavities revealed that there was NO air moving through the affected side on each horse however, endoscopic exam revealed a unique problem in each horse.

Figure 1

 In Figure 1, a smooth, white soft tissue mass was identified within 2 inches of the opening of the nasal cavity. This soft tissue mass was completely obstructing the nasal passage. In addition, when the scope was passed through the unaffected side, the soft tissue mass was noted to be extending into the naso-pharynx suggesting that the soft tissue mass extended through out the entire nasal passage (Figure 2). In Figure 2, the white wall of tissue noted along the right side of the image is the soft tissue mass as it extends into the naso-pharynx.The soft tissue mass is most likely consistent with a paranasal sinus cyst however surgical removal will be required to confirm the diagnosis. These types of cysts develop in young horses and grow slowly over months and years until a clinical problem develops. Surgical removal provides complete resolution of these types of cysts!!

Figure 2

Figure 3

In the second horse, a large golden-colored soft tissue mass was identified in the region of the nasal passage closest to the naso-pharynx. There was more discharge associated with this soft tissue mass and small areas of hemorrhage were noted. The soft tissue mass was completely obstructing the nasal passage and was originating from the ethmoid turbinate region which most likely classified it as a ethmoid hematoma!! These types of tumors typically present with a complaint of a unilateral bloody nasal discharge for months before they completely obstruct the nasal passage. However, they can be fast growing tumors and require an aggressive approach to eradicate. Treatment may involve either surgical removal or repeated injections of formalin. It has been my experience, having injected several horses for YEARS, that the tumors tend to return with this approach! Hence, I recommend surgical removal when first diagnosed, especially if the tumor is invading the sinus cavity or the naso-pharynx.