Which option below is a fungal infection that can cause upper airway disease with nasal discharge in horses?

• A. GP Mycosis
• B. Strangles
• C. Cicatrix
• D. Neoplasia

Answer: (A)

Guttural pouch mycosis is a fungal infection that can produce upper airway signs in horses, most notably unilateral nasal discharge. The fungus (often Aspergillus) grows on the mucosal lining of the guttural pouch and can erode nearby vessels and nerves, leading to discharge that drips into the nasal cavity and, in some cases, nosebleeds or cranial nerve–related signs. On endoscopy you may see whitish, cottony fungal plaques inside the guttural pouch, which helps confirm the diagnosis. Treatment typically involves delivering antifungal medications directly into the guttural pouch (topical irrigation with agents like enilconazole) and managing any bleeding or complications as needed.

The other options describe nonfungal causes of nasal discharge. Strangles is a bacterial infection that causes fever, swollen lymph nodes, and purulent nasal discharge rather than a fungal growth in the guttural pouch. Cicatrix refers to scar tissue that could affect airflow but isn’t infectious. Neoplasia involves tumors that can cause nasal discharge but are not fungal infections.